Hypothalamic Area, Lateral
Hypothalamus, Anterior
Anterior Hypothalamic Nucleus
Hypothalamus
Hypothalamic Hormones
Dorsomedial Hypothalamic Nucleus
Neuropeptides
Arcuate Nucleus
Mamillary Bodies
Pituitary Hormones
Hypothalamus, Middle
Hypothalamus, Posterior
Orexin Receptors
Neurons
Diencephalon
Median Eminence
Microinjections
Proto-Oncogene Proteins c-fos
Melanins
Autonomic Pathways
Ventromedial Hypothalamic Nucleus
Neuropeptide Y
Amyotrophic Lateral Sclerosis
Receptors, Neuropeptide
Intracellular Signaling Peptides and Proteins
Neurotensin
Rats, Sprague-Dawley
Anorexia
Feeding Behavior
Saline Solution, Hypertonic
Sodium, Dietary
Wakefulness
Pro-Opiomelanocortin
Brain
Brain Stem
Sleep
Gonadotropin-Releasing Hormone
Body Temperature Regulation
Immunohistochemistry
Rats, Inbred SHR
Lateral Line System
Rats, Wistar
Rats, Inbred WKY
Norepinephrine
Leptin
Cholera Toxin
In Situ Hybridization
Brain Mapping
Rats, Inbred Strains
Body Weight
Luteinizing Hormone
Lateral Ventricles
RNA, Messenger
Geniculate Bodies
Lateral hypothalamic NMDA receptor subunits NR2A and/or NR2B mediate eating: immunochemical/behavioral evidence. (1/191)
Cells within the lateral hypothalamic area (LHA) are important in eating control. Glutamate or its analogs, kainic acid (KA) and N-methyl-D-aspartate (NMDA), elicit intense eating when microinjected there, and, conversely, LHA-administered NMDA receptor antagonists suppress deprivation- and NMDA-elicited eating. The subunit composition of LHA NMDA receptors (NMDA-Rs) mediating feeding, however, has not yet been determined. Identifying this is important, because distinct second messengers/modulators may be activated by NMDA-Rs with differing compositions. To begin to address this, we detected LHA NR2A and NR2B subunits by immunoblotting and NR2B subunits by immunohistochemistry using subunit-specific antibodies. To help determine whether NMDA-Rs mediating feeding might contain these subunits, we conducted behavioral studies using LHA-administered ifenprodil, an antagonist selective for NR2A- and/or NR2B-containing NMDA-Rs at the doses we used (0.001-100 nmol). Ifenprodil maximally suppressed NMDA- and deprivation-elicited feeding by 63 and 39%, respectively, but failed to suppress KA-elicited eating, suggesting its actions were behaviorally specific. Collectively, these results suggest that LHA NMDA-Rs, some of which contribute to feeding control, are composed of NR2A and/or NR2B subunits, and implicate NR2A- and/or NR2B-linked signal transduction in feeding behavior. (+info)Hypothalamic hypocretin (orexin): robust innervation of the spinal cord. (2/191)
Hypocretin (orexin) is synthesized by neurons in the lateral hypothalamus and has been reported to increase food intake and regulate the neuroendocrine system. In the present paper, long descending axonal projections that contain hypocretin were found that innervate all levels of the spinal cord from cervical to sacral segments, as studied in mouse, rat, and human spinal cord and not previously described. High densities of axonal innervation are found in regions of the spinal cord related to modulation of sensation and pain, notably in the marginal zone (lamina 1). Innervation of the intermediolateral column and lamina 10 as well as strong innervation of the caudal region of the sacral cord suggest that hypocretin may participate in the regulation of both the sympathetic and parasympathetic parts of the autonomic nervous system. Double-labeling experiments in mice combining retrograde transport of diamidino yellow after spinal cord injections and immunocytochemistry support the concept that hypocretin-immunoreactive fibers in the cord originate from the neurons in the lateral hypothalamus. Digital-imaging physiological studies with fura-2 detected a rise in intracellular calcium in response to hypocretin in cultured rat spinal cord neurons, indicating that spinal cord neurons express hypocretin-responsive receptors. A greater number of cervical cord neurons responded to hypocretin than another hypothalamo-spinal neuropeptide, oxytocin. These data suggest that in addition to possible roles in feeding and endocrine regulation, the descending hypocretin fiber system may play a role in modulation of sensory input, particularly in regions of the cord related to pain perception and autonomic tone. (+info)Microinjection of leptin into the ventromedial hypothalamus increases glucose uptake in peripheral tissues in rats. (3/191)
We studied the effects of microinjection of leptin into the ventromedial hypothalamus (VMH) and lateral hypothalamus (LH) on glucose uptake in peripheral tissues in unanesthetized rats. The rate of glucose uptake was assessed in vivo by 2-[3H]deoxyglucose incorporation. Single injection of leptin into VMH increased glucose uptake in brown adipose tissue (BAT), heart, skeletal muscles, and spleen but not in white adipose tissue or skin. On the other hand, microinjection of leptin into LH had little effect on glucose uptake in those tissues. The plasma concentrations of glucose and insulin were unaltered by intrahypothalamic injection of leptin into either VMH or LH. Among skeletal muscles, the increase in glucose uptake induced by intrahypothalamic injection of leptin was greater in the soleus than in the extensor digitorum longus. Likewise, the increased glucose uptake in the gastrocnemius in response to leptin was more prominent in the red part than in the white part of the tissue. When surgical sympathetic denervation of the interscapular BAT was performed, the enhanced glucose uptake by BAT in response to intrahypothalamic leptin was completely suppressed. These findings suggest that intrahypothalamic injection of leptin preferentially increases glucose uptake by some peripheral tissues through activation of the VMH-sympathetic (or its neighboring medial hypothalamus-sympathetic) nervous system, thereby contributing to the maintenance of energy balance. (+info)Distinct patterns of neuropeptide gene expression in the lateral hypothalamic area and arcuate nucleus are associated with dehydration-induced anorexia. (4/191)
We have investigated the hormonal and hypothalamic neuropeptidergic substrates of dehydration-associated anorexia. In situ hybridization and hormone analyses of anorexic and paired food-restricted rats revealed two distinct profiles. First, both groups had the characteristic gene expression and endocrine signatures usually associated with starvation: increased neuropeptide Y and decreased proopiomelanocortin and neurotensin mRNAs in the arcuate nucleus (ARH); increased circulating glucocorticoid but reduced leptin and insulin. Dehydrated animals are strongly anorexic despite these attributes, showing that the output of leptin- and insulin-sensitive ARH neurons that ordinarily stimulate eating must be inhibited. The second pattern occurred only in anorexic animals and had two components: (1) reduced corticotropin-releasing hormone (CRH) mRNA in the neuroendocrine paraventricular nucleus (PVH) and (2) increased CRH and neurotensin mRNAs in the lateral hypothalamic (LHA) and retrochiasmatic areas. However, neither corticosterone nor suppressed PVH CRH gene expression is required for anorexia after dehydration because PVH CRH mRNA in dehydrated adrenalectomized animals is unchanged from euhydrated adrenalectomized controls. We also showed that LHA CRH mRNA was strongly correlated with the intensity of anorexia, increased LHA CRH gene expression preceded the onset of anorexia, and dehydrated adrenalectomized animals (which also develop anorexia) had elevated LHA CRH gene expression with a distribution pattern similar to intact animals. Finally, we identified specific efferents from the CRH-containing region of the LHA to the PVH, thereby providing a neuroanatomical framework for the integration by the PVH of neuropeptidergic signals from the ARH and the LHA. Together, these observations suggest that CRH and neurotensin neurons in the LHA constitute a novel anatomical substrate for their well known anorexic effects. (+info)Lateral hypothalamic serotonin inhibits nucleus accumbens dopamine: implications for sexual satiety. (5/191)
Dopamine (DA) is released in several brain areas, including the nucleus accumbens (NAcc), before and during copulation in male rats. DA agonists administered into this area facilitate, and DA antagonists inhibit, numerous motivated behaviors, including male sexual behavior. Serotonin (5-HT) is generally inhibitory to male sexual behavior. We reported previously that 5-HT is released in the anterior lateral hypothalamic area (LHA(A)) and that a selective serotonin reuptake inhibitor microinjected into that area delayed and slowed copulation. Our present results, using high temporal resolution microdialysis, (1) confirm previous electrochemical evidence that extracellular levels of DA increase in the NAcc during copulation and decrease during the postejaculatory interval (PEI) and (2) reveal that LHA(A) 5-HT can inhibit both basal and female-elicited DA release in the NAcc. These findings suggest that the neural circuit promoting sexual quiescence during the PEI includes serotonergic input to the LHA(A), which in turn inhibits DA release in the NAcc. These findings may also provide insights concerning the inhibitory control of other motivated behaviors activated by the NAcc and may have relevance for understanding the sexual side effects common to antidepressant medications. (+info)Leptin differentially regulates NPY and POMC neurons projecting to the lateral hypothalamic area. (6/191)
Recent studies have reinforced the view that the lateral hypothalamic area (LHA) regulates food intake and body weight. We identified leptin-sensitive neurons in the arcuate nucleus of the hypothalamus (Arc) that innervate the LHA using retrograde tracing with leptin administration. We found that retrogradely labeled cells in the Arc contained neuropeptide Y (NPY) mRNA or proopiomelanocortin (POMC) mRNA. Following leptin administration, NPY cells in the Arc did not express Fos but expressed suppressor of cytokine signaling-3 (SOCS-3) mRNA. In contrast, leptin induced both Fos and SOCS-3 expression in POMC neurons, many of which also innervated the LHA. These findings suggest that leptin directly and differentially engages NPY and POMC neurons that project to the LHA, linking circulating leptin and neurons that regulate feeding behavior and body weight homeostasis. (+info)Hypothalamic orexin expression: modulation by blood glucose and feeding. (7/191)
Orexins (hypocretins), novel peptides expressed in specific neurons of the lateral hypothalamic area (LHA), stimulate feeding when injected intracerebroventricularly. We investigated their role in feeding in the rat by measuring hypothalamic prepro-orexin mRNA levels under contrasting conditions of increased hunger. Prepro-orexin mRNA levels increased significantly after 48 h of fasting (by 90-170%; P < 0.05) and after acute (6 h) hypoglycemia when food was withheld (by 90%; P < 0.02). By contrast, levels were unchanged during chronic food restriction, streptozotocin-induced diabetes, hypoglycemia when food was available, voluntary overconsumption of palatable food, or glucoprivation induced by systemic 2-deoxy-D-glucose. Orexin expression was not obviously related to changes in body weight, insulin, or leptin, but was stimulated under conditions of low plasma glucose in the absence of food. Orexins may participate in the short-term regulation of energy homeostasis by initiating feeding in response to falls in glucose and terminating it after food ingestion. The LHA is known to contain neurons that are stimulated by falls in circulating glucose but inhibited by feeding-related signals from the viscera; orexin neurons may correspond to this neuronal population. (+info)Evidence of a functional relationship between the nucleus accumbens shell and lateral hypothalamus subserving the control of feeding behavior. (8/191)
Inhibition of neurons in the nucleus accumbens shell (AcbSh) with local injections of GABA agonists or glutamate antagonists elicits an intense, but specific, feeding response resembling that seen after stimulation of the lateral hypothalamus (LH). To help characterize the contribution of the LH to the expression of AcbSh-mediated feeding, we used the immunohistochemical detection of the nuclear protein Fos to determine whether inhibition of AcbSh cells results in an activation of LH neurons. Injections of the GABA(A) agonist muscimol into the AcbSh greatly increased the number of cells exhibiting Fos-like immunoreactivity in the LH, as well as in the lateral septum, paraventricular hypothalamic nucleus, ventral tegmental area, substantia nigra pars compacta, and nucleus of the solitary tract. Blocking activation of LH neurons with the selective NMDA receptor blocker D(-)-AP-5 is known to suppress deprivation-induced feeding. We found that injections of D(-)-AP5 into the LH also dose-dependently suppressed AcbSh-mediated feeding. It is likely that inhibition of GABAergic neurons in the AcbSh is responsible for eliciting this feeding. If a behaviorally relevant GABAergic projection terminates in the LH, we should be able to mimic the effects seen after inhibition of the projection neurons by applying a GABA receptor blocker to the area. However, injections of the GABA(A) receptor blocker bicuculline or the GABA(B) receptor blocker saclofen did not significantly affect food intake. Thus, it appears that the expression of the feeding response depends on an NMDA-preferring receptor-mediated activation of LH neurons and is not the result of disinhibiting LH cells by disrupting transmission at GABA synapses. (+info)The lateral hypothalamic area (LHA) is a region in the hypothalamus, which is a part of the brain that plays a crucial role in regulating various autonomic functions and maintaining homeostasis. The LHA is located laterally to the third ventricle and contains several neuronal populations that are involved in diverse physiological processes such as feeding behavior, energy balance, sleep-wake regulation, and neuroendocrine function.
Some of the key neurons found in the LHA include orexin/hypocretin neurons, melanin-concentrating hormone (MCH) neurons, and agouti-related protein (AGRP) neurons. These neurons release neurotransmitters and neuropeptides that modulate various physiological functions, including appetite regulation, energy expenditure, and arousal. Dysfunction in the LHA has been implicated in several neurological and psychiatric disorders, such as narcolepsy, obesity, and depression.
The anterior hypothalamus is a region in the brain that has various functions related to endocrine regulation, autonomic function, and behavior. It contains several nuclei, including the paraventricular nucleus and the supraoptic nucleus, which are involved in the release of hormones from the pituitary gland. The anterior hypothalamus helps regulate body temperature, hunger, thirst, fatigue, and sleep-wake cycles. It also plays a role in processing emotions and stress responses. Damage to the anterior hypothampus can result in various endocrine and behavioral disorders.
The anterior hypothalamic nucleus is a collection of neurons located in the rostral (front) part of the hypothalamus, a region of the brain that plays a crucial role in regulating various autonomic functions and behaviors. The anterior hypothalamic nucleus is involved in several physiological processes, including:
1. Temperature regulation: The anterior hypothalamic nucleus helps maintain body temperature within a normal range by integrating information from thermal receptors and modulating the activity of the autonomic nervous system to promote heat production or dissipation as needed.
2. Energy balance: This region is involved in regulating energy intake and expenditure through its connections with other hypothalamic nuclei, such as the arcuate nucleus, that control feeding behavior and metabolism.
3. Sleep-wake regulation: The anterior hypothalamic nucleus contains neurons that are active during wakefulness and contribute to arousal. It also contains sleep-promoting neurons that help facilitate transitions from wakefulness to sleep.
4. Stress response: The anterior hypothalamic nucleus is part of the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the body's stress response. It releases corticotropin-releasing hormone (CRH), which stimulates the release of adrenocorticotropic hormone (ACTH) from the pituitary gland and ultimately leads to the production and release of cortisol, a steroid hormone involved in the stress response.
5. Emotional regulation: The anterior hypothalamic nucleus has connections with limbic structures such as the amygdala and hippocampus, which are involved in emotional processing. Dysfunction in this region has been implicated in mood disorders like depression and anxiety.
In summary, the anterior hypothalamic nucleus is a critical component of the hypothalamus that plays a significant role in regulating various physiological processes, including temperature regulation, energy balance, sleep-wake regulation, stress response, and emotional regulation.
The hypothalamus is a small, vital region of the brain that lies just below the thalamus and forms part of the limbic system. It plays a crucial role in many important functions including:
1. Regulation of body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.
2. Production and regulation of hormones through its connection with the pituitary gland (the hypophysis). It controls the release of various hormones by producing releasing and inhibiting factors that regulate the anterior pituitary's function.
3. Emotional responses, behavior, and memory formation through its connections with the limbic system structures like the amygdala and hippocampus.
4. Autonomic nervous system regulation, which controls involuntary physiological functions such as heart rate, blood pressure, and digestion.
5. Regulation of the immune system by interacting with the autonomic nervous system.
Damage to the hypothalamus can lead to various disorders like diabetes insipidus, growth hormone deficiency, altered temperature regulation, sleep disturbances, and emotional or behavioral changes.
The preoptic area (POA) is a region within the anterior hypothalamus of the brain. It is named for its location near the optic chiasm, where the optic nerves cross. The preoptic area is involved in various functions, including body temperature regulation, sexual behavior, and sleep-wake regulation.
The preoptic area contains several groups of neurons that are sensitive to changes in temperature and are responsible for generating heat through shivering or non-shivering thermogenesis. It also contains neurons that release inhibitory neurotransmitters such as GABA and galanin, which help regulate arousal and sleep.
Additionally, the preoptic area has been implicated in the regulation of sexual behavior, particularly in males. Certain populations of neurons within the preoptic area are involved in the expression of male sexual behavior, such as mounting and intromission.
Overall, the preoptic area is a critical region for the regulation of various physiological and behavioral functions, making it an important area of study in neuroscience research.
Hypothalamic hormones are a group of hormones that are produced and released by the hypothalamus, a small region at the base of the brain. These hormones play a crucial role in regulating various bodily functions, including temperature, hunger, thirst, sleep, and emotional behavior.
The hypothalamus produces two main types of hormones: releasing hormones and inhibiting hormones. Releasing hormones stimulate the pituitary gland to release its own hormones, while inhibiting hormones prevent the pituitary gland from releasing hormones.
Some examples of hypothalamic hormones include:
* Thyroid-releasing hormone (TRH), which stimulates the release of thyroid-stimulating hormone (TSH) from the pituitary gland.
* Growth hormone-releasing hormone (GHRH) and somatostatin, which regulate the release of growth hormone (GH) from the pituitary gland.
* Gonadotropin-releasing hormone (GnRH), which stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland, which in turn regulate reproductive function.
* Corticotropin-releasing hormone (CRH), which stimulates the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, which regulates the stress response.
* Prolactin-inhibiting hormone (PIH) and prolactin-releasing hormone (PRH), which regulate the release of prolactin from the pituitary gland, which is involved in lactation.
Overall, hypothalamic hormones play a critical role in maintaining homeostasis in the body by regulating various physiological processes.
The dorsomedial hypothalamic nucleus (DMH) is a collection of neurons located in the dorsomedial region of the hypothalamus, a part of the brain that regulates various autonomic and endocrine functions. The DMH plays a critical role in regulating several physiological processes, including feeding behavior, energy balance, body temperature, and circadian rhythms.
The neurons in the DMH release different neurotransmitters, such as glutamate, GABA, and neuropeptides, that modulate its functions. The DMH receives inputs from various brain regions, including the limbic system, which is involved in emotional processing, and the brainstem, which regulates autonomic functions.
The DMH also projects to several brain areas, such as the paraventricular hypothalamic nucleus (PVN), lateral hypothalamus, and other regions of the brainstem, forming a complex neural network that controls energy balance and feeding behavior. Dysfunction in the DMH has been implicated in various pathological conditions, including obesity, diabetes, and mood disorders.
Neuropeptides are small protein-like molecules that are used by neurons to communicate with each other and with other cells in the body. They are produced in the cell body of a neuron, processed from larger precursor proteins, and then transported to the nerve terminal where they are stored in secretory vesicles. When the neuron is stimulated, the vesicles fuse with the cell membrane and release their contents into the extracellular space.
Neuropeptides can act as neurotransmitters or neuromodulators, depending on their target receptors and the duration of their effects. They play important roles in a variety of physiological processes, including pain perception, appetite regulation, stress response, and social behavior. Some neuropeptides also have hormonal functions, such as oxytocin and vasopressin, which are produced in the hypothalamus and released into the bloodstream to regulate reproductive and cardiovascular function, respectively.
There are hundreds of different neuropeptides that have been identified in the nervous system, and many of them have multiple functions and interact with other signaling molecules to modulate neural activity. Dysregulation of neuropeptide systems has been implicated in various neurological and psychiatric disorders, such as chronic pain, addiction, depression, and anxiety.
The arcuate nucleus is a part of the hypothalamus in the brain. It is involved in the regulation of various physiological functions, including appetite, satiety, and reproductive hormones. The arcuate nucleus contains two main types of neurons: those that produce neuropeptide Y and agouti-related protein, which stimulate feeding and reduce energy expenditure; and those that produce pro-opiomelanocortin and cocaine-and-amphetamine-regulated transcript, which suppress appetite and increase energy expenditure. These neurons communicate with other parts of the brain to help maintain energy balance and reproductive function.
The mamillary bodies are a pair of small, round structures located in the hypothalamus region of the brain. They play a crucial role in the limbic system, which is involved in emotions, memory, and learning. Specifically, the mamillary bodies are part of the circuit that forms the Papez circuit, a neural network responsible for memory and cognitive functions.
The mamillary bodies receive inputs from several brain regions, including the hippocampus, anterior thalamic nuclei, and cingulate gyrus. They then project this information to the thalamus, which in turn sends it to the cerebral cortex for further processing.
Damage to the mamillary bodies can result in memory impairment, as seen in patients with Korsakoff's syndrome, a condition often associated with chronic alcohol abuse.
Pituitary hormones are chemical messengers produced and released by the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland is often referred to as the "master gland" because it controls several other endocrine glands and regulates various bodily functions.
There are two main types of pituitary hormones: anterior pituitary hormones and posterior pituitary hormones, which are produced in different parts of the pituitary gland and have distinct functions.
Anterior pituitary hormones include:
1. Growth hormone (GH): regulates growth and metabolism.
2. Thyroid-stimulating hormone (TSH): stimulates the thyroid gland to produce thyroid hormones.
3. Adrenocorticotropic hormone (ACTH): stimulates the adrenal glands to produce cortisol and other steroid hormones.
4. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): regulate reproductive function in both males and females.
5. Prolactin: stimulates milk production in lactating women.
6. Melanocyte-stimulating hormone (MSH): regulates skin pigmentation and appetite.
Posterior pituitary hormones include:
1. Oxytocin: stimulates uterine contractions during childbirth and milk ejection during lactation.
2. Vasopressin (antidiuretic hormone, ADH): regulates water balance in the body by controlling urine production in the kidneys.
Overall, pituitary hormones play crucial roles in regulating growth, development, metabolism, reproductive function, and various other bodily functions. Abnormalities in pituitary hormone levels can lead to a range of medical conditions, such as dwarfism, acromegaly, Cushing's disease, infertility, and diabetes insipidus.
I believe you may be referring to the "ventral" part of the hypothalamus, as there isn't a widely recognized anatomical division called the "middle" hypothalamus. The ventral hypothalamus is a region that contains several critical structures, including:
1. The infundibular stem: This is a funnel-shaped structure that extends downward from the hypothalamus and forms the beginning of the pituitary stalk. It contains tuber cinereum and the median eminence.
2. Tuber cinereum: A region with several nuclei, including the arcuate nucleus, which plays a role in regulating feeding behavior, growth hormone release, and sexual function.
3. Median eminence: A crucial area where the hypothalamus interacts with the pituitary gland. It contains nerve terminals that release neurohormones into the portal capillaries, which then carry these substances to the anterior pituitary to regulate hormone secretion.
The ventral hypothalamus is essential for various functions, such as releasing and inhibiting hormones, regulating body temperature, hunger, thirst, sleep, emotional behavior, and parental behaviors.
Neural pathways, also known as nerve tracts or fasciculi, refer to the highly organized and specialized routes through which nerve impulses travel within the nervous system. These pathways are formed by groups of neurons (nerve cells) that are connected in a series, creating a continuous communication network for electrical signals to transmit information between different regions of the brain, spinal cord, and peripheral nerves.
Neural pathways can be classified into two main types: sensory (afferent) and motor (efferent). Sensory neural pathways carry sensory information from various receptors in the body (such as those for touch, temperature, pain, and vision) to the brain for processing. Motor neural pathways, on the other hand, transmit signals from the brain to the muscles and glands, controlling movements and other effector functions.
The formation of these neural pathways is crucial for normal nervous system function, as it enables efficient communication between different parts of the body and allows for complex behaviors, cognitive processes, and adaptive responses to internal and external stimuli.
The posterior hypothalamus is a region in the brain that plays a crucial role in various autonomic functions. It is located in the posterior part of the hypothalamus, which is a small region at the base of the brain that helps regulate many bodily functions, including body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.
The posterior hypothalamus contains several groups of neurons that are involved in the regulation of autonomic responses, such as the control of heart rate, blood pressure, and body temperature. It also plays a role in the regulation of hormones released from the pituitary gland, which is located below the hypothalamus.
One important function of the posterior hypothalamus is to help regulate body temperature. When the body's temperature rises, neurons in the posterior hypothalamus detect this change and send signals to other parts of the brain to initiate responses that help cool the body down, such as sweating and dilation of blood vessels near the skin surface. Conversely, when the body's temperature drops, the posterior hypothalamus helps to generate heat by stimulating muscle contractions and constricting blood vessels in the skin.
Overall, the posterior hypothalamus is an essential component of the brain's complex system for maintaining homeostasis and regulating various physiological functions.
Stilbamidines are a class of chemical compounds that are primarily used as veterinary medicines, specifically as parasiticides for the treatment and prevention of ectoparasites such as ticks and lice in livestock animals. Stilbamidines belong to the family of chemicals known as formamidines, which are known to have insecticidal and acaricidal properties.
The most common stilbamidine compound is chlorphentermine, which has been used as an appetite suppressant in human medicine. However, its use as a weight loss drug was discontinued due to its addictive properties and potential for serious side effects.
It's important to note that Stilbamidines are not approved for use in humans and should only be used under the supervision of a veterinarian for the intended purpose of treating and preventing ectoparasites in animals.
Orexin receptors are a type of G protein-coupled receptor found in the central nervous system that play a crucial role in regulating various physiological functions, including wakefulness, energy balance, and reward processing. There are two subtypes of orexin receptors: OX1R (orexin-1 receptor) and OX2R (orexin-2 receptor). These receptors bind to the neuropeptides orexin A and orexin B, which are synthesized in a small group of neurons located in the hypothalamus. Activation of these receptors leads to increased wakefulness, appetite stimulation, and reward-seeking behavior, among other effects. Dysregulation of the orexin system has been implicated in several neurological disorders, such as narcolepsy, where a loss of orexin-producing neurons results in excessive daytime sleepiness and cataplexy.
Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.
The diencephalon is a term used in anatomy to refer to the part of the brain that lies between the cerebrum and the midbrain. It includes several important structures, such as the thalamus, hypothalamus, epithalamus, and subthalamus.
The thalamus is a major relay station for sensory information, receiving input from all senses except smell and sending it to the appropriate areas of the cerebral cortex. The hypothalamus plays a crucial role in regulating various bodily functions, including hunger, thirst, body temperature, and sleep-wake cycles. It also produces hormones that regulate mood, growth, and development.
The epithalamus contains the pineal gland, which produces melatonin, a hormone that helps regulate sleep-wake cycles. The subthalamus is involved in motor control and coordination.
Overall, the diencephalon plays a critical role in integrating sensory information, regulating autonomic functions, and modulating behavior and emotion.
The Paraventricular Hypothalamic Nucleus (PVN) is a nucleus in the hypothalamus, which is a part of the brain that regulates various autonomic functions and homeostatic processes. The PVN plays a crucial role in the regulation of neuroendocrine and autonomic responses to stress, as well as the control of fluid and electrolyte balance, cardiovascular function, and energy balance.
The PVN is composed of several subdivisions, including the magnocellular and parvocellular divisions. The magnocellular neurons produce and release two neuropeptides, oxytocin and vasopressin (also known as antidiuretic hormone), into the circulation via the posterior pituitary gland. These neuropeptides play important roles in social behavior, reproduction, and fluid balance.
The parvocellular neurons, on the other hand, project to various brain regions and the pituitary gland, where they release neurotransmitters and neuropeptides that regulate the hypothalamic-pituitary-adrenal (HPA) axis, which is responsible for the stress response. The PVN also contains neurons that produce corticotropin-releasing hormone (CRH), a key neurotransmitter involved in the regulation of the HPA axis and the stress response.
Overall, the Paraventricular Hypothalamic Nucleus is an essential component of the brain's regulatory systems that help maintain homeostasis and respond to stressors. Dysfunction of the PVN has been implicated in various pathological conditions, including hypertension, obesity, and mood disorders.
The median eminence is a small, elevated region located at the base of the hypothalamus in the brain. It plays a crucial role in the regulation of the endocrine system by controlling the release of hormones from the pituitary gland. The median eminence contains numerous specialized blood vessels called portal capillaries that carry hormones and neurotransmitters from the hypothalamus to the anterior pituitary gland.
The median eminence is also the site where several releasing and inhibiting hormones produced in the hypothalamus are secreted into the portal blood vessels, which then transport them to the anterior pituitary gland. These hormones include thyroid-stimulating hormone (TSH) releasing hormone, growth hormone-releasing hormone, prolactin-inhibiting hormone, and gonadotropin-releasing hormone, among others.
Once these hormones reach the anterior pituitary gland, they bind to specific receptors on the surface of target cells, triggering a cascade of intracellular signals that ultimately lead to the synthesis and release of various pituitary hormones. In this way, the median eminence serves as an essential link between the nervous system and the endocrine system, allowing for precise regulation of hormone secretion and overall homeostasis in the body.
Microinjection is a medical technique that involves the use of a fine, precise needle to inject small amounts of liquid or chemicals into microscopic structures, cells, or tissues. This procedure is often used in research settings to introduce specific substances into individual cells for study purposes, such as introducing DNA or RNA into cell nuclei to manipulate gene expression.
In clinical settings, microinjections may be used in various medical and cosmetic procedures, including:
1. Intracytoplasmic Sperm Injection (ICSI): A type of assisted reproductive technology where a single sperm is injected directly into an egg to increase the chances of fertilization during in vitro fertilization (IVF) treatments.
2. Botulinum Toxin Injections: Microinjections of botulinum toxin (Botox, Dysport, or Xeomin) are used for cosmetic purposes to reduce wrinkles and fine lines by temporarily paralyzing the muscles responsible for their formation. They can also be used medically to treat various neuromuscular disorders, such as migraines, muscle spasticity, and excessive sweating (hyperhidrosis).
3. Drug Delivery: Microinjections may be used to deliver drugs directly into specific tissues or organs, bypassing the systemic circulation and potentially reducing side effects. This technique can be particularly useful in treating localized pain, delivering growth factors for tissue regeneration, or administering chemotherapy agents directly into tumors.
4. Gene Therapy: Microinjections of genetic material (DNA or RNA) can be used to introduce therapeutic genes into cells to treat various genetic disorders or diseases, such as cystic fibrosis, hemophilia, or cancer.
Overall, microinjection is a highly specialized and precise technique that allows for the targeted delivery of substances into small structures, cells, or tissues, with potential applications in research, medical diagnostics, and therapeutic interventions.
Proto-oncogene proteins, such as c-Fos, are normal cellular proteins that play crucial roles in various biological processes including cell growth, differentiation, and survival. They can be activated or overexpressed due to genetic alterations, leading to the formation of cancerous cells. The c-Fos protein is a nuclear phosphoprotein involved in signal transduction pathways and forms a heterodimer with c-Jun to create the activator protein-1 (AP-1) transcription factor complex. This complex binds to specific DNA sequences, thereby regulating the expression of target genes that contribute to various cellular responses, including proliferation, differentiation, and apoptosis. Dysregulation of c-Fos can result in uncontrolled cell growth and malignant transformation, contributing to tumor development and progression.
Melanin is a pigment that determines the color of skin, hair, and eyes in humans and animals. It is produced by melanocytes, which are specialized cells found in the epidermis (the outer layer of the skin) and the choroid (the vascular coat of the eye). There are two main types of melanin: eumelanin and pheomelanin. Eumelanin is a black or brown pigment, while pheomelanin is a red or yellow pigment. The amount and type of melanin produced by an individual can affect their skin and hair color, as well as their susceptibility to certain diseases, such as skin cancer.
The autonomic nervous system (ANS) is a component of the peripheral nervous system that regulates involuntary physiological functions, such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. The autonomic pathways refer to the neural connections and signaling processes that allow the ANS to carry out these functions.
The autonomic pathways consist of two main subdivisions: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). These systems have opposing effects on many organs, with the SNS generally stimulating activity and the PNS inhibiting it. The enteric nervous system, which controls gut function, is sometimes considered a third subdivision of the ANS.
The sympathetic pathway originates in the thoracic and lumbar regions of the spinal cord, with preganglionic neurons synapsing on postganglionic neurons in paravertebral ganglia or prevertebral ganglia. The parasympathetic pathway originates in the brainstem (cranial nerves III, VII, IX, and X) and the sacral region of the spinal cord (S2-S4), with preganglionic neurons synapsing on postganglionic neurons near or within the target organ.
Acetylcholine is the primary neurotransmitter used in both the sympathetic and parasympathetic pathways, although norepinephrine (noradrenaline) is also released by some postganglionic sympathetic neurons. The specific pattern of neural activation and inhibition within the autonomic pathways helps maintain homeostasis and allows for adaptive responses to changes in the internal and external environment.
The ventromedial hypothalamic nucleus (VMN) is a collection of neurons located in the ventromedial region of the hypothalamus, a part of the brain that regulates various autonomic and endocrine functions. The VMN plays an essential role in regulating several physiological processes, including feeding behavior, energy balance, and glucose homeostasis. It contains neurons that are sensitive to changes in nutrient status, such as leptin and insulin levels, and helps to integrate this information with other signals to modulate food intake and energy expenditure. Additionally, the VMN has been implicated in the regulation of various emotional and motivational states, including anxiety, fear, and reward processing.
The medical definition of "eating" refers to the process of consuming and ingesting food or nutrients into the body. This process typically involves several steps, including:
1. Food preparation: This may involve cleaning, chopping, cooking, or combining ingredients to make them ready for consumption.
2. Ingestion: The act of taking food or nutrients into the mouth and swallowing it.
3. Digestion: Once food is ingested, it travels down the esophagus and enters the stomach, where it is broken down by enzymes and acids to facilitate absorption of nutrients.
4. Absorption: Nutrients are absorbed through the walls of the small intestine and transported to cells throughout the body for use as energy or building blocks for growth and repair.
5. Elimination: Undigested food and waste products are eliminated from the body through the large intestine (colon) and rectum.
Eating is an essential function that provides the body with the nutrients it needs to maintain health, grow, and repair itself. Disorders of eating, such as anorexia nervosa or bulimia nervosa, can have serious consequences for physical and mental health.
Neuropeptide Y (NPY) is a neurotransmitter and neuropeptide that is widely distributed in the central and peripheral nervous systems. It is a member of the pancreatic polypeptide family, which includes peptide YY and pancreatic polypeptide. NPY plays important roles in various physiological functions such as energy balance, feeding behavior, stress response, anxiety, memory, and cardiovascular regulation. It is involved in the modulation of neurotransmitter release, synaptic plasticity, and neural development. NPY is synthesized from a larger precursor protein called prepro-NPY, which is post-translationally processed to generate the mature NPY peptide. The NPY system has been implicated in various pathological conditions such as obesity, depression, anxiety disorders, hypertension, and drug addiction.
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder that affects nerve cells in the brain and spinal cord responsible for controlling voluntary muscle movements, such as speaking, walking, breathing, and swallowing. The condition is characterized by the degeneration of motor neurons in the brain (upper motor neurons) and spinal cord (lower motor neurons), leading to their death.
The term "amyotrophic" comes from the Greek words "a" meaning no or negative, "myo" referring to muscle, and "trophic" relating to nutrition. When a motor neuron degenerates and can no longer send impulses to the muscle, the muscle becomes weak and eventually atrophies due to lack of use.
The term "lateral sclerosis" refers to the hardening or scarring (sclerosis) of the lateral columns of the spinal cord, which are primarily composed of nerve fibers that carry information from the brain to the muscles.
ALS is often called Lou Gehrig's disease, named after the famous American baseball player who was diagnosed with the condition in 1939. The exact cause of ALS remains unknown, but it is believed to involve a combination of genetic and environmental factors. There is currently no cure for ALS, and treatment primarily focuses on managing symptoms and maintaining quality of life.
The progression of ALS varies from person to person, with some individuals experiencing rapid decline over just a few years, while others may have a more slow-progressing form of the disease that lasts several decades. The majority of people with ALS die from respiratory failure within 3 to 5 years after the onset of symptoms. However, approximately 10% of those affected live for 10 or more years following diagnosis.
Neuropeptide receptors are a type of cell surface receptor that bind to neuropeptides, which are small signaling molecules made up of short chains of amino acids. These receptors play an important role in the nervous system by mediating the effects of neuropeptides on various physiological processes, including neurotransmission, pain perception, and hormone release.
Neuropeptide receptors are typically composed of seven transmembrane domains and are classified into several families based on their structure and function. Some examples of neuropeptide receptor families include the opioid receptors, somatostatin receptors, and vasoactive intestinal peptide (VIP) receptors.
When a neuropeptide binds to its specific receptor, it activates a signaling pathway within the cell that leads to various cellular responses. These responses can include changes in gene expression, ion channel activity, and enzyme function. Overall, the activation of neuropeptide receptors helps to regulate many important functions in the body, including mood, appetite, and pain sensation.
Intracellular signaling peptides and proteins are molecules that play a crucial role in transmitting signals within cells, which ultimately lead to changes in cell behavior or function. These signals can originate from outside the cell (extracellular) or within the cell itself. Intracellular signaling molecules include various types of peptides and proteins, such as:
1. G-protein coupled receptors (GPCRs): These are seven-transmembrane domain receptors that bind to extracellular signaling molecules like hormones, neurotransmitters, or chemokines. Upon activation, they initiate a cascade of intracellular signals through G proteins and secondary messengers.
2. Receptor tyrosine kinases (RTKs): These are transmembrane receptors that bind to growth factors, cytokines, or hormones. Activation of RTKs leads to autophosphorylation of specific tyrosine residues, creating binding sites for intracellular signaling proteins such as adapter proteins, phosphatases, and enzymes like Ras, PI3K, and Src family kinases.
3. Second messenger systems: Intracellular second messengers are small molecules that amplify and propagate signals within the cell. Examples include cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), diacylglycerol (DAG), inositol triphosphate (IP3), calcium ions (Ca2+), and nitric oxide (NO). These second messengers activate or inhibit various downstream effectors, leading to changes in cellular responses.
4. Signal transduction cascades: Intracellular signaling proteins often form complex networks of interacting molecules that relay signals from the plasma membrane to the nucleus. These cascades involve kinases (protein kinases A, B, C, etc.), phosphatases, and adapter proteins, which ultimately regulate gene expression, cell cycle progression, metabolism, and other cellular processes.
5. Ubiquitination and proteasome degradation: Intracellular signaling pathways can also control protein stability by modulating ubiquitin-proteasome degradation. E3 ubiquitin ligases recognize specific substrates and conjugate them with ubiquitin molecules, targeting them for proteasomal degradation. This process regulates the abundance of key signaling proteins and contributes to signal termination or amplification.
In summary, intracellular signaling pathways involve a complex network of interacting proteins that relay signals from the plasma membrane to various cellular compartments, ultimately regulating gene expression, metabolism, and other cellular processes. Dysregulation of these pathways can contribute to disease development and progression, making them attractive targets for therapeutic intervention.
Neurotensin is a neuropeptide that is widely distributed in the central nervous system and the gastrointestinal tract. It is composed of 13 amino acids and plays a role as a neurotransmitter or neuromodulator in various physiological functions, including pain regulation, temperature regulation, and feeding behavior. Neurotensin also has been shown to have potential roles in the development of certain diseases such as cancer and neurological disorders. It exerts its effects by binding to specific receptors, known as neurotensin receptors (NTSR1, NTSR2, and NTSR3), which are widely distributed throughout the body.
Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.
Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.
These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.
Anorexia is a medical condition defined as a loss of appetite or aversion to food, leading to significant weight loss. It can be a symptom of various underlying causes, such as mental health disorders (most commonly an eating disorder called anorexia nervosa), gastrointestinal issues, cancer, infections, or side effects of medication. In this definition, we are primarily referring to anorexia as a symptom rather than the specific eating disorder anorexia nervosa.
Anorexia nervosa is a psychological eating disorder characterized by:
1. Restriction of energy intake leading to significantly low body weight (in context of age, sex, developmental trajectory, and physical health)
2. Intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain
3. Disturbed body image, such as overvaluation of self-worth regarding shape or weight, or denial of the seriousness of low body weight
Anorexia nervosa has two subtypes: restricting type and binge eating/purging type. The restricting type involves limiting food intake without engaging in binge eating or purging behaviors (such as self-induced vomiting or misuse of laxatives, diuretics, or enemas). In contrast, the binge eating/purging type includes recurrent episodes of binge eating and compensatory behaviors to prevent weight gain.
It is essential to differentiate between anorexia as a symptom and anorexia nervosa as a distinct psychological disorder when discussing medical definitions.
Feeding behavior refers to the various actions and mechanisms involved in the intake of food and nutrition for the purpose of sustaining life, growth, and health. This complex process encompasses a coordinated series of activities, including:
1. Food selection: The identification, pursuit, and acquisition of appropriate food sources based on sensory cues (smell, taste, appearance) and individual preferences.
2. Preparation: The manipulation and processing of food to make it suitable for consumption, such as chewing, grinding, or chopping.
3. Ingestion: The act of transferring food from the oral cavity into the digestive system through swallowing.
4. Digestion: The mechanical and chemical breakdown of food within the gastrointestinal tract to facilitate nutrient absorption and eliminate waste products.
5. Assimilation: The uptake and utilization of absorbed nutrients by cells and tissues for energy production, growth, repair, and maintenance.
6. Elimination: The removal of undigested material and waste products from the body through defecation.
Feeding behavior is regulated by a complex interplay between neural, hormonal, and psychological factors that help maintain energy balance and ensure adequate nutrient intake. Disruptions in feeding behavior can lead to various medical conditions, such as malnutrition, obesity, eating disorders, and gastrointestinal motility disorders.
A hypertonic saline solution is a type of medical fluid that contains a higher concentration of salt (sodium chloride) than is found in the average person's blood. This solution is used to treat various medical conditions, such as dehydration, brain swelling, and increased intracranial pressure.
The osmolarity of a hypertonic saline solution typically ranges from 1500 to 23,400 mOsm/L, with the most commonly used solutions having an osmolarity of around 3000 mOsm/L. The high sodium concentration in these solutions creates an osmotic gradient that draws water out of cells and into the bloodstream, helping to reduce swelling and increase fluid volume in the body.
It is important to note that hypertonic saline solutions should be administered with caution, as they can cause serious side effects such as electrolyte imbalances, heart rhythm abnormalities, and kidney damage if not used properly. Healthcare professionals must carefully monitor patients receiving these solutions to ensure safe and effective treatment.
Dietary sodium is a mineral that is primarily found in table salt (sodium chloride) and many processed foods. It is an essential nutrient for human health, playing a crucial role in maintaining fluid balance, transmitting nerve impulses, and regulating muscle contractions. However, consuming too much dietary sodium can increase blood pressure and contribute to the development of hypertension, heart disease, stroke, and kidney problems.
The recommended daily intake of dietary sodium is less than 2,300 milligrams (mg) per day for most adults, but the American Heart Association recommends no more than 1,500 mg per day for optimal heart health. It's important to note that many processed and restaurant foods contain high levels of sodium, so it's essential to read food labels and choose fresh, whole foods whenever possible to help limit dietary sodium intake.
Wakefulness is a state of consciousness in which an individual is alert and aware of their surroundings. It is characterized by the ability to perceive, process, and respond to stimuli in a purposeful manner. In a medical context, wakefulness is often assessed using measures such as the electroencephalogram (EEG) to evaluate brain activity patterns associated with consciousness.
Wakefulness is regulated by several interconnected neural networks that promote arousal and attention. These networks include the ascending reticular activating system (ARAS), which consists of a group of neurons located in the brainstem that project to the thalamus and cerebral cortex, as well as other regions involved in regulating arousal and attention, such as the basal forebrain and hypothalamus.
Disorders of wakefulness can result from various underlying conditions, including neurological disorders, sleep disorders, medication side effects, or other medical conditions that affect brain function. Examples of such disorders include narcolepsy, insomnia, hypersomnia, and various forms of encephalopathy or brain injury.
Pro-opiomelanocortin (POMC) is a precursor protein that gets cleaved into several biologically active peptides in the body. These peptides include adrenocorticotropic hormone (ACTH), beta-lipotropin, and multiple opioid peptides such as beta-endorphin, met-enkephalin, and leu-enkephalin.
ACTH stimulates the release of cortisol from the adrenal gland, while beta-lipotropin has various metabolic functions. The opioid peptides derived from POMC have pain-relieving (analgesic) and rewarding effects in the brain. Dysregulation of the POMC system has been implicated in several medical conditions, including obesity, addiction, and certain types of hormone deficiencies.
The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:
1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.
The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.
The brainstem is the lower part of the brain that connects to the spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls many vital functions such as heart rate, breathing, and blood pressure. It also serves as a relay center for sensory and motor information between the cerebral cortex and the rest of the body. Additionally, several cranial nerves originate from the brainstem, including those that control eye movements, facial movements, and hearing.
Sleep is a complex physiological process characterized by altered consciousness, relatively inhibited sensory activity, reduced voluntary muscle activity, and decreased interaction with the environment. It's typically associated with specific stages that can be identified through electroencephalography (EEG) patterns. These stages include rapid eye movement (REM) sleep, associated with dreaming, and non-rapid eye movement (NREM) sleep, which is further divided into three stages.
Sleep serves a variety of functions, including restoration and strengthening of the immune system, support for growth and development in children and adolescents, consolidation of memory, learning, and emotional regulation. The lack of sufficient sleep or poor quality sleep can lead to significant health problems, such as obesity, diabetes, cardiovascular disease, and even cognitive decline.
The American Academy of Sleep Medicine (AASM) defines sleep as "a period of daily recurring natural rest during which consciousness is suspended and metabolic processes are reduced." However, it's important to note that the exact mechanisms and purposes of sleep are still being researched and debated among scientists.
Gonadotropin-Releasing Hormone (GnRH), also known as Luteinizing Hormone-Releasing Hormone (LHRH), is a hormonal peptide consisting of 10 amino acids. It is produced and released by the hypothalamus, an area in the brain that links the nervous system to the endocrine system via the pituitary gland.
GnRH plays a crucial role in regulating reproduction and sexual development through its control of two gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These gonadotropins, in turn, stimulate the gonads (ovaries or testes) to produce sex steroids and eggs or sperm.
GnRH acts on the anterior pituitary gland by binding to its specific receptors, leading to the release of FSH and LH. The hypothalamic-pituitary-gonadal axis is under negative feedback control, meaning that when sex steroid levels are high, they inhibit the release of GnRH, which subsequently decreases FSH and LH secretion.
GnRH agonists and antagonists have clinical applications in various medical conditions, such as infertility treatments, precocious puberty, endometriosis, uterine fibroids, prostate cancer, and hormone-responsive breast cancer.
Body temperature regulation, also known as thermoregulation, is the process by which the body maintains its core internal temperature within a narrow range, despite varying external temperatures. This is primarily controlled by the hypothalamus in the brain, which acts as a thermostat and receives input from temperature receptors throughout the body. When the body's temperature rises above or falls below the set point, the hypothalamus initiates responses to bring the temperature back into balance. These responses can include shivering to generate heat, sweating to cool down, vasodilation or vasoconstriction of blood vessels to regulate heat loss, and changes in metabolic rate. Effective body temperature regulation is crucial for maintaining optimal physiological function and overall health.
Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.
SHR (Spontaneously Hypertensive Rats) are an inbred strain of rats that were originally developed through selective breeding for high blood pressure. They are widely used as a model to study hypertension and related cardiovascular diseases, as well as neurological disorders such as stroke and dementia.
Inbred strains of animals are created by mating genetically identical individuals (siblings or offspring) for many generations, resulting in a population that is highly homozygous at all genetic loci. This means that the animals within an inbred strain are essentially genetically identical to one another, which makes them useful for studying the effects of specific genes or environmental factors on disease processes.
SHR rats develop high blood pressure spontaneously, without any experimental manipulation, and show many features of human hypertension, such as increased vascular resistance, left ventricular hypertrophy, and renal dysfunction. They also exhibit a number of behavioral abnormalities, including hyperactivity, impulsivity, and cognitive deficits, which make them useful for studying the neurological consequences of hypertension and other cardiovascular diseases.
Overall, inbred SHR rats are an important tool in biomedical research, providing a valuable model for understanding the genetic and environmental factors that contribute to hypertension and related disorders.
The lateral line system is a sensory organ found in aquatic animals, such as fish and some aquatic amphibians. It is a series of fluid-filled canals and sensory cells that run along the sides of the body, head, and fins. These sensory cells are called neuromasts and contain hair cells that respond to vibrations and water movements. The lateral line system helps these animals detect movement, pressure changes, and vibrations in their aquatic environment, which aids in schooling behavior, prey detection, and avoiding predators.
"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.
Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.
Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.
WKY (Wistar Kyoto) is not a term that refers to "rats, inbred" in a medical definition. Instead, it is a strain of laboratory rat that is widely used in biomedical research. WKY rats are an inbred strain, which means they are the result of many generations of brother-sister matings, resulting in a genetically uniform population.
WKY rats originated from the Wistar Institute in Philadelphia and were established as a normotensive control strain to contrast with other rat strains that exhibit hypertension. They have since been used in various research areas, including cardiovascular, neurological, and behavioral studies. Compared to other commonly used rat strains like the spontaneously hypertensive rat (SHR), WKY rats are known for their lower blood pressure, reduced stress response, and greater emotionality.
In summary, "WKY" is a designation for an inbred strain of laboratory rat that is often used as a control group in biomedical research due to its normotensive characteristics.
Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.
As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.
In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.
Leptin is a hormone primarily produced and released by adipocytes, which are the fat cells in our body. It plays a crucial role in regulating energy balance and appetite by sending signals to the brain when the body has had enough food. This helps control body weight by suppressing hunger and increasing energy expenditure. Leptin also influences various metabolic processes, including glucose homeostasis, neuroendocrine function, and immune response. Defects in leptin signaling can lead to obesity and other metabolic disorders.
Cholera toxin is a protein toxin produced by the bacterium Vibrio cholerae, which causes the infectious disease cholera. The toxin is composed of two subunits, A and B, and its primary mechanism of action is to alter the normal function of cells in the small intestine.
The B subunit of the toxin binds to ganglioside receptors on the surface of intestinal epithelial cells, allowing the A subunit to enter the cell. Once inside, the A subunit activates a signaling pathway that results in the excessive secretion of chloride ions and water into the intestinal lumen, leading to profuse, watery diarrhea, dehydration, and other symptoms associated with cholera.
Cholera toxin is also used as a research tool in molecular biology and immunology due to its ability to modulate cell signaling pathways. It has been used to study the mechanisms of signal transduction, protein trafficking, and immune responses.
In situ hybridization (ISH) is a molecular biology technique used to detect and localize specific nucleic acid sequences, such as DNA or RNA, within cells or tissues. This technique involves the use of a labeled probe that is complementary to the target nucleic acid sequence. The probe can be labeled with various types of markers, including radioisotopes, fluorescent dyes, or enzymes.
During the ISH procedure, the labeled probe is hybridized to the target nucleic acid sequence in situ, meaning that the hybridization occurs within the intact cells or tissues. After washing away unbound probe, the location of the labeled probe can be visualized using various methods depending on the type of label used.
In situ hybridization has a wide range of applications in both research and diagnostic settings, including the detection of gene expression patterns, identification of viral infections, and diagnosis of genetic disorders.
Brain mapping is a broad term that refers to the techniques used to understand the structure and function of the brain. It involves creating maps of the various cognitive, emotional, and behavioral processes in the brain by correlating these processes with physical locations or activities within the nervous system. Brain mapping can be accomplished through a variety of methods, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scans, electroencephalography (EEG), and others. These techniques allow researchers to observe which areas of the brain are active during different tasks or thoughts, helping to shed light on how the brain processes information and contributes to our experiences and behaviors. Brain mapping is an important area of research in neuroscience, with potential applications in the diagnosis and treatment of neurological and psychiatric disorders.
Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.
In a medical context, electric stimulation may be used for various purposes such as:
1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.
It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.
"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.
Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.
Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.
Body weight is the measure of the force exerted on a scale or balance by an object's mass, most commonly expressed in units such as pounds (lb) or kilograms (kg). In the context of medical definitions, body weight typically refers to an individual's total weight, which includes their skeletal muscle, fat, organs, and bodily fluids.
Healthcare professionals often use body weight as a basic indicator of overall health status, as it can provide insights into various aspects of a person's health, such as nutritional status, metabolic function, and risk factors for certain diseases. For example, being significantly underweight or overweight can increase the risk of developing conditions like malnutrition, diabetes, heart disease, and certain types of cancer.
It is important to note that body weight alone may not provide a complete picture of an individual's health, as it does not account for factors such as muscle mass, bone density, or body composition. Therefore, healthcare professionals often use additional measures, such as body mass index (BMI), waist circumference, and blood tests, to assess overall health status more comprehensively.
Luteinizing Hormone (LH) is a glycoprotein hormone, which is primarily produced and released by the anterior pituitary gland. In women, a surge of LH triggers ovulation, the release of an egg from the ovaries during the menstrual cycle. During pregnancy, LH stimulates the corpus luteum to produce progesterone. In men, LH stimulates the testes to produce testosterone. It plays a crucial role in sexual development, reproduction, and maintaining the reproductive system.
The lateral ventricles are a pair of fluid-filled cavities located within the brain. They are part of the ventricular system, which is a series of interconnected spaces filled with cerebrospinal fluid (CSF). The lateral ventricles are situated in the left and right hemispheres of the brain and are among the largest of the ventricles.
Each lateral ventricle has a complex structure and can be divided into several parts:
1. Anterior horn: This is the front part of the lateral ventricle, located in the frontal lobe of the brain.
2. Body: The central part of the lateral ventricle, which is continuous with the anterior horn and posterior horn.
3. Posterior horn: The back part of the lateral ventricle, located in the occipital lobe of the brain.
4. Temporal horn: An extension that projects into the temporal lobe of the brain.
The lateral ventricles are lined with ependymal cells, which produce cerebrospinal fluid. CSF circulates through the ventricular system, providing buoyancy and protection to the brain, and is eventually absorbed into the bloodstream. Abnormalities in the size or shape of the lateral ventricles can be associated with various neurological conditions, such as hydrocephalus, brain tumors, or neurodegenerative diseases.
Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.
Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:
1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.
Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.
In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.
For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.
Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.
Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.
The geniculate bodies are part of the auditory pathway in the brainstem. They are two small, rounded eminences located on the lateral side of the upper pons, near the junction with the midbrain. The geniculate bodies are divided into an anterior and a posterior portion, known as the anterior and posterior geniculate bodies, respectively.
The anterior geniculate body receives inputs from the contralateral cochlear nucleus via the trapezoid body, and it is involved in the processing of sound localization. The posterior geniculate body receives inputs from the inferior colliculus via the lateral lemniscus and is involved in the processing of auditory information for conscious perception.
Overall, the geniculate bodies play a critical role in the processing and transmission of auditory information to higher brain areas for further analysis and interpretation.
Hypertension is a medical term used to describe abnormally high blood pressure in the arteries, often defined as consistently having systolic blood pressure (the top number in a blood pressure reading) over 130 mmHg and/or diastolic blood pressure (the bottom number) over 80 mmHg. It is also commonly referred to as high blood pressure.
Hypertension can be classified into two types: primary or essential hypertension, which has no identifiable cause and accounts for about 95% of cases, and secondary hypertension, which is caused by underlying medical conditions such as kidney disease, hormonal disorders, or use of certain medications.
If left untreated, hypertension can lead to serious health complications such as heart attack, stroke, heart failure, and chronic kidney disease. Therefore, it is important for individuals with hypertension to manage their condition through lifestyle modifications (such as healthy diet, regular exercise, stress management) and medication if necessary, under the guidance of a healthcare professional.
Hypothalamus
Neuropeptide
Medial forebrain bundle
Orexin
Mesolimbic pathway
Reward system
Retinohypothalamic tract
Gigantocellular reticular nucleus
Stria medullaris of thalamus
Slow-wave sleep
Bioenergetics
Energy homeostasis
PGRMC1
Nucleus raphe pallidus
Arcuate nucleus
Hypothalamic-pituitary-adrenal axis
LHA
Stria terminalis
Nucleus raphe magnus
Edinger-Westphal nucleus
Dorsal tegmental nucleus
Neurotransmitter
Vasopressin receptor 1A
Ventrolateral preoptic nucleus
Hippocampus anatomy
Narcolepsy
Setmelanotide
List of MeSH codes (A08)
Reticular formation
Ventral tegmental area
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Hypothalamus28
- Activity-dependent tagging revealed a subset of ventral tegmental area γ-aminobutyric acid (GABA)-somatostatin (VTA Vgat-Sst ) cells that sense stress and drive non-rapid eye movement (NREM) and REM sleep through the lateral hypothalamus and also inhibit corticotropin-releasing factor (CRF) release in the paraventricular hypothalamus. (nih.gov)
- citation needed] The hypothalamic nuclei include the following: Cross-section of the monkey hypothalamus displays two of the major hypothalamic nuclei on either side of the fluid-filled third ventricle. (wikipedia.org)
- Hypothalamic nuclei Hypothalamic nuclei on one side of the hypothalamus, shown in a 3-D computer reconstruction The hypothalamus is highly interconnected with other parts of the central nervous system, in particular the brainstem and its reticular formation. (wikipedia.org)
- Projections to areas caudal to the hypothalamus go through the medial forebrain bundle, the mammillotegmental tract and the dorsal longitudinal fasciculus. (wikipedia.org)
- Projections to areas rostral to the hypothalamus are carried by the mammillothalamic tract, the fornix and terminal stria. (wikipedia.org)
- Outside the canonical hypothalamic feeding circuits involved in energy homeostasis and the notion of "feeding center," we focused on lateral hypothalamus as neural substrate able to confront food-associated homeostatic information with food salience, motivation to eat, reward-seeking, and development of compulsive eating. (frontiersin.org)
- Thus, the lateral hypothalamus-ventral tegmental area-nucleus accumbens neural circuitry is reexamined in order to interrogate the functional interplay between ghrelin, dopamine, orexin, and endocannabinoid signaling. (frontiersin.org)
- We suggested a pivotal role for endocannabinoids in food reward processing within the lateral hypothalamus, and for orexin neurons to integrate endocrine signals with food reinforcement and hedonic eating. (frontiersin.org)
- Finally, type-1 cannabinoid receptor-dependent inhibition of GABA-ergic release and relapse to reward-associated stimuli is linked to ghrelin and orexin signaling in the lateral hypothalamus-ventral tegmental area-nucleus accumbens network to highlight its pathological potential for food addiction-like behavior. (frontiersin.org)
- Leptin acts on various brain regions including the hypothalamus, ventral tegmental area, and hindbrain ( 2 , , , , , , , - 10 ) and regulates energy homeostasis by triggering decreased food consumption and increased energy expenditure. (diabetesjournals.org)
- Scholars@Duke publication: Appetitive changes during salt deprivation are paralleled by widespread neuronal adaptations in nucleus accumbens, lateral hypothalamus, and central amygdala. (duke.edu)
- Because forebrain areas such as the lateral hypothalamus (LH), central amygdala (CeA), and nucleus accumbens (NAc) are known to play an important role in this behavior, we recorded from these areas while water-deprived (WD) and salt-deprived (SD) rats performed a two-bottle choice test between 0.5 M salt (NaCl) and 0.4 M sucrose. (duke.edu)
- Imai's team traced Sirt1's impact on aging to the hypothalamus, specifically the dorsomedial and lateral hypothalamic nuclei, and identified genes related to those areas that respond to elevated levels of the Sirt1 protein by sending nerve signals that delay the onset of the aging process. (goldsea.com)
- We found that overexpression of Sirt1 in the brain leads to an increase in the cellular response of a receptor called orexin type 2 receptor in the two areas of the hypothalamus," said Akiko Satoh, a postdoc in Imai's lab who served as the study's first author. (goldsea.com)
- Body 1 Schematic drawings of coronal areas through the ovine hypothalamus and POA depicting the distribution of NK3R-IR cells. (exposed-skin-care.net)
- Two areas of the hypothalamus are known to be particularly important in eating. (pressbooks.pub)
- The lateral part of the hypothalamus responds primarily to cues to start eating, whereas the ventromedial part of the hypothalamus primarily responds to cues to stop eating. (pressbooks.pub)
- If the lateral part of the hypothalamus is damaged, the animal will not eat even if food is present, whereas if the ventromedial part of the hypothalamus is damaged, the animal will eat until it is obese (Wolf & Miller, 1964). (pressbooks.pub)
- Kisspeptin, also known as metastin, serves as a gatekeeper of puberty and is mainly expressed in the hypothalamus of rodents, especially the arcuate nucleus (ARC) and the anterioventral periventricular nucleus (AVPV) areas [12], in addition to the paraventricular nucleus and amygdala [13]. (researchsquare.com)
- Electrical stimulation of the lateral hypothalamus (ESLH), which causes satiated animals to eat, resembles in effect the hunger normally produced by deprivation of food in that it also motivates them to perform a response that they previously had learned as a way of getting food (1). (nyu.edu)
- There is evidence that Y4 receptor stimulation results in LH release, and studies from our laboratory show Y4-like immunoreactivity in the majority of orexin cell bodies in the lateral hypothalamic area and some orexin fibers scattered throughout the hypothalamus. (elsevierpure.com)
- Interestingly, mRNA levels of SIRT1 are selectively increased in the lateral hypothalamic area (LHA) and ventromedial hypothalamus (VMH) in HD. (lu.se)
- 2] Superiorly, the hypothalamus is divided from the thalamus by a groove in the lateral wall of the third ventricle, the hypothalamic sulcus. (medscape.com)
- The lateral region is largely composed of a massive bidirectional fiber pathway, the medial forebrain bundle (MFB), which connects the hypothalamus to the limbic system and brainstem autonomic centers. (medscape.com)
- 2] Through the MFB, signals from the brainstem, amygdala, hippocampus, retina, and olfactory system are conveyed to hypothalamic nuclei, underlying the crucial role of the hypothalamus in systemic homeostasis. (medscape.com)
- D) coronal sections of the hypothalamus, reflecting relative positions of hypothalamic nuclei. (medscape.com)
- Nuclei within the anterior subdivision of the hypothalamus include the medial/lateral preoptic, periventricular, supraoptic, suprachiasmatic, and anterior/lateral hypothalamic nuclei. (medscape.com)
- The arcuate nucleus median eminence area, a region with a weak blood-brain barrier, contains at least two neuronal cell populations that exert opposing actions on energy balance.some other nucleus and other neuropeptides secreted from the hypothalamus regulate the feeding behaviour. (journalcra.com)
Neurons8
- Some differences are apparent even in gross neuroanatomy: most notable is the sexually dimorphic nucleus within the preoptic area, in which the differences are subtle changes in the connectivity and chemical sensitivity of particular sets of neurons. (wikipedia.org)
- Increase of energy accumulation elicits leptin release and simultaneous inhibition of orexigenic neurons expressing neuropeptide Y (NPY) and agouti-related peptide (AgRP), as well as activation of the anorexigenic proopiomelanocortin (POMC) neurons within the hypothalamic arcuate nucleus (ARC). (frontiersin.org)
- Figure 3: Neurotransmitter phenotypes in hypothalamic neurons. (nature.com)
- Moreover, orexins have been reported to greatly influence gonadotropin-releasing hormone neurons and their secretions to regulate reproductive functions via modulation of the hypothalamic-pituitary-gonadal axis. (researchgate.net)
- In all areas, compared with those recorded during the WD state, neurons recorded during the SD state showed an increase in the percentage of salt-evoked excitatory responses and a decrease in the percentage of sucrose-evoked inhibitory responses, suggesting that a subset of the neuronal population in these areas codes for the increased motivational and/or hedonic value of the salt solution. (duke.edu)
- In addition, in the SD state, the firing of excitatory neurons in LH and CeA became more synchronized, indicating a greater functional connectivity between salt-responsive neurons in these areas. (duke.edu)
- The orexins are produced in neurons of the lateral hypothalamic area and implicated in the regulation of both feeding and reproductive function. (elsevierpure.com)
- The present study found that, although Y4-positive orexin fibers are in present in the area of GnRH neurons, they never come in close contact with GnRH neurons. (elsevierpure.com)
Nuclei5
- Hypothalamic nuclei are located within these specific regions and areas. (wikipedia.org)
- Neural brain circuits integrate information from the NTS and multiple hypothalamic nuclei to regulate overall body homeostasis. (medscape.com)
- Subunit alpha6-immunoreactivity was only present in granule cells of the cerebellum and the cochlear nucleus, and subunit gamma1-immunoreactivity was preferentially located in the central and medial amygdaloid nuclei, in pallidal areas, the substantia nigra pars reticulata and the inferior olive. (nih.gov)
- Although the lateral region is the most voluminous, the medial and periventricular regions contain the majority of hypothalamic nuclei. (medscape.com)
- The medial preoptic nucleus abuts the third ventricle and periventricular nucleus medially and is bound laterally by the lateral preoptic nucleus, superiorly by the anterior commissure, and inferiorly by the supraoptic and suprachiasmatic nuclei. (medscape.com)
Ventromedial2
- These include hypothalamic areas such as the ventromedial nucleus, dorsomedial nucleus and the lateral hypothalamic area, which modulate this control system. (medscape.com)
- Recently we showed that 24 h after copulation to satiety, there is a reduction in androgen receptor density (ARd) in the medial preoptic area (MPOA) and in the ventromedial hypothalamic nucleus (VMH), but not in the bed nucleus of the stria terminalis (BST). (karger.com)
Amygdala3
- As part of the limbic system, it has connections to other limbic structures including the amygdala and septum, and is also connected with areas of the autonomous nervous system. (wikipedia.org)
- The amygdala area lies in the roof of the inferior horn between the rostral end of the horn and the basal ganglia. (ehd.org)
- The present study was designed to analyze whether the ARd changes in these and other brain areas, such as the medial amygdala (MeA) and lateral septum, ventral part (LSV), were associated with changes in sexual behavior following sexual satiety. (karger.com)
Arcuate nucleus-median eminence1
- The hypothalamic arcuate nucleus-median eminence is a target for sustained diabetes remission induced by fibroblast growth factor 1. (nature.com)
Neuronal6
- Perineuronal net formation during the critical period for neuronal maturation in the hypothalamic arcuate nucleus. (nature.com)
- Overall, our catalog of neuronal subclasses provides new understanding of hypothalamic organization and function. (nature.com)
- Figure 4: Neuropeptide associations to individual hypothalamic neuronal subtypes. (nature.com)
- Both neuronal populations innervate the paraventricular nucleus, which, in turn, sends signals to other areas of the brain. (medscape.com)
- We propose that plastic changes in the feeding-related neuronal populations of these forebrain areas arise when changes in metabolic state alter the hedonic and motivational value of a particular taste stimulus. (duke.edu)
- Several hypothalamic peptides that participate in the control of ingestive behavior are produced in neuronal cell bodies of the arcuate nucleus and/ or the lateral hypothalamic area. (journalcra.com)
Paraventricular1
- One of the most prominent and thick populations of NK3R-IR neurones apart from the ARC had been observed in the next locations (in descending purchase of overall cellular number): the hypothalamic paraventricular nucleus (PVN) lateral hypothalamic region (LHA) ventral premammillary nucleus (PMv) Rch and POA. (exposed-skin-care.net)
Orexins1
- Orexins (or hypocretins) are hypothalamic neuropeptides with a multitude of physiological functions. (researchgate.net)
Ventricle2
Olfactory1
- In marsupials and monotremes, cortical gradients of laminar elaboration expand from allocortical areas (primary olfactory and hippocampal areas) of 2-3 layers to periallocortical and proisocortical areas of 5 layers that lack or have rudimentary granular layer IV (Abbie 1940 , 1942 ). (springer.com)
Regulates3
- Next, endocannabinoid signaling that regulates synaptic plasticity is discussed as a key mechanism acting both at hypothalamic and mesolimbic circuits, and affecting both dopamine function and interplay between leptin and ghrelin signaling. (frontiersin.org)
- The hypothalamic-pituitary-gonadal (HPG) axis regulates the ovary activity along with menstruation period. (researchsquare.com)
- The lateral hypothalamic area (LHA) regulates food intake and energy balance. (bvsalud.org)
Thalamus1
- The lateral surface is contiguous with the thalamus and subthalamus and is bordered by the internal capsule and optic tracts. (medscape.com)
Coronal1
- and three areas (periventricular, medial, lateral) in the coronal plane, indicating location medial-lateral. (wikipedia.org)
Food intake1
- Within this context, leptin provides the adipocyte-derived hormonal signaling allowing the bidirectional communication between adipose tissue and hypothalamic regulation of food intake and energy expenditure ( Zhou and Rui, 2013 ). (frontiersin.org)
Huntingtin1
- Quantitative real-time polymerase chain reactions were used to assess levels of SIRT1-3 and downstream targets in post mortem brain tissue from HD patients and control cases as well as after selective hypothalamic expression of mutant huntingtin (HTT) using recombinant adeno-associated viral vectors in mice. (lu.se)
Caudal1
- Caudal approach, lateral view. (medscape.com)
Behavior1
- The results are discussed on the basis of the similarities and discrepancies between ARd in specific brain areas and male sexual behavior. (karger.com)
Rats3
- Fig. 2: T2D-ZDF rats exhibit abnormal hypothalamic CS/DS-GAG sulfation patterns. (nature.com)
- In the present article, we perform cortical type analysis of the neocortex of adult rats, Rhesus macaques, and humans to propose hypotheses on homology of cortical areas applying the principles of the Hypothesis on the Dual Origin of the Neocortex. (springer.com)
- We show that areas in the outer rings of the neocortex have comparable laminar elaboration in rats and primates, while most 6-layer eulaminate areas in the innermost rings of primate neocortex lack homologous counterparts in rats. (springer.com)
Brain2
- Rewarding electrical stimulation was delivered via electrodes stereotaxically implanted in the medial forebrain bundle-lateral hypothalamic area of the rat brain. (erowid.org)
- Areas of the brain involved in sleep arousal and therefore being awake and reactive to stimuli are also important as they control food-seeking behaviour. (vetsci.co.uk)
Axis1
- these effects appear to be mediated by changes in the gonadal-hypothalamic-pituitary axis. (cdc.gov)
Projections1
- Projections to areas of the sympathetic motor system (lateral horn spinal segments T1-L2/L3) are carried by the hypothalamospinal tract and they activate the sympathetic motor pathway. (wikipedia.org)
Endocrine1
- Investigators have hitherto relied on candidate protein-based tools to correlate behavioral, endocrine and gender traits with hypothalamic neuron identity. (nature.com)
Cortical areas1
- Distribution of inputs across cortex Percent of tagged inputs to cholinergic beginner cells across all cortical areas is demonstrated per subject matter (individual pubs clustered in sets of three). (mycareerpeer.com)
Forebrain areas1
- Thus, alpha2-subunit-immunoreactivity was preferentially located in forebrain areas and the cerebellum. (nih.gov)
Expression1
- Analyses after selective hypothalamic expression of mutant HTT suggest that effects on BDNF, orexin, dynorphin and MCH are early and direct, whereas changes in SIRT1 require more widespread expression of mutant HTT. (lu.se)
Inhibit1
- It synthesizes and secretes certain neurohormones, called releasing hormones or hypothalamic hormones, and these in turn stimulate or inhibit the secretion of hormones from the pituitary gland. (wikipedia.org)
Distinct1
- A distinct chin becomes evident in the midline at the ventral end of the mandibular area. (ehd.org)
Control1
- Although in keeping with previously findings we discovered no cases of NK3R colocalization in GnRH neurones in either the POA or MBH >70% GnRH neurones in both areas had been approached by NK3R-IR presynaptic terminals recommending that furthermore to its function at KNDy cell physiques NKB may control GnRH neurones by presynaptic activities. (exposed-skin-care.net)
Primarily1
- These subdivisions are derived primarily from the hypothalamic blood supply. (medscape.com)
Rostral1
- The rostral part of the ridge divides into medial and lateral portions. (ehd.org)