A central nervous system stimulant used most commonly in the treatment of ATTENTION DEFICIT DISORDER in children and for NARCOLEPSY. Its mechanisms appear to be similar to those of DEXTROAMPHETAMINE. The d-isomer of this drug is referred to as DEXMETHYLPHENIDATE HYDROCHLORIDE.
A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here.
A behavior disorder originating in childhood in which the essential features are signs of developmentally inappropriate inattention, impulsivity, and hyperactivity. Although most individuals have symptoms of both inattention and hyperactivity-impulsivity, one or the other pattern may be predominant. The disorder is more frequent in males than females. Onset is in childhood. Symptoms often attenuate during late adolescence although a minority experience the full complement of symptoms into mid-adulthood. (From DSM-V)
Propylamines are organic compounds consisting of an amino group (-NH2) attached to a propyl group (CH3CH2CH2-), which can act as central nervous system stimulants, local anesthetics, or vasopressors, depending on their specific chemical structure.
Drugs that block the transport of DOPAMINE into axon terminals or into storage vesicles within terminals. Most of the ADRENERGIC UPTAKE INHIBITORS also inhibit dopamine uptake.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of dopaminergic neurons. They remove DOPAMINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS and are the target of DOPAMINE UPTAKE INHIBITORS.
Drugs that block the transport of adrenergic transmitters into axon terminals or into storage vesicles within terminals. The tricyclic antidepressants (ANTIDEPRESSIVE AGENTS, TRICYCLIC) and amphetamines are among the therapeutically important drugs that may act via inhibition of adrenergic transport. Many of these drugs also block transport of serotonin.
The d-form of AMPHETAMINE. It is a central nervous system stimulant and a sympathomimetic. It has also been used in the treatment of narcolepsy and of attention deficit disorders and hyperactivity in children. Dextroamphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulating release of monamines, and inhibiting monoamine oxidase. It is also a drug of abuse and a psychotomimetic.
Dosage forms of a drug that act over a period of time by controlled-release processes or technology.
A powerful central nervous system stimulant and sympathomimetic. Amphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulation of release of monamines, and inhibiting monoamine oxidase. Amphetamine is also a drug of abuse and a psychotomimetic. The l- and the d,l-forms are included here. The l-form has less central nervous system activity but stronger cardiovascular effects. The d-form is DEXTROAMPHETAMINE.
Excessive movement of muscles of the body as a whole, which may be associated with organic or psychological disorders.
The relationship between the dose of an administered drug and the response of the organism to the drug.
One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.
Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)
A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.
A substituted benzamide that has antipsychotic properties. It is a dopamine D2 receptor (see RECEPTORS, DOPAMINE D2) antagonist.
The physical activity of a human or an animal as a behavioral phenomenon.
A central nervous system stimulant used in fatigue and depressive states and to treat hyperkinetic disorders in children.
The observable response an animal makes to any situation.
Lack of emotion or emotional expression; a disorder of motivation that persists over time.
Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.
A central nervous system stimulant and sympathomimetic with actions and uses similar to DEXTROAMPHETAMINE. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed.
An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of noradrenergic neurons. They remove NOREPINEPHRINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. It regulates signal amplitude and duration at noradrenergic synapses and is the target of ADRENERGIC UPTAKE INHIBITORS.
A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)
A ketose sugar that is commonly used in the commercial synthesis of ASCORBIC ACID.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
An isoquinoline derivative that prevents dopamine reuptake into synaptosomes. The maleate was formerly used in the treatment of depression. It was withdrawn worldwide in 1986 due to the risk of acute hemolytic anemia with intravascular hemolysis resulting from its use. In some cases, renal failure also developed. (From Martindale, The Extra Pharmacopoeia, 30th ed, p266)
Administration of a drug or chemical by the individual under the direction of a physician. It includes administration clinically or experimentally, by human or animal.
Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.
Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.
A technique to self-regulate brain activities provided as a feedback in order to better control or enhance one's own performance, control or function. This is done by trying to bring brain activities into a range associated with a desired brain function or status.
Biogenic amines having only one amine moiety. Included in this group are all natural monoamines formed by the enzymatic decarboxylation of natural amino acids.
The tendency to explore or investigate a novel environment. It is considered a motivation not clearly distinguishable from curiosity.

Further analysis of the separate and interactive effects of methylphenidate and common classroom contingencies. (1/610)

We evaluated separate and interactive effects between common classroom contingencies and methylphenidate (MPH) on disruptive and off-task behaviors for 4 children with a diagnosis of attention deficit hyperactivity disorder. Analogue conditions consisting of contingent teacher reprimands, brief time-out, no interaction, and alone were conducted in a multielement design. Medication status (MPH or placebo) was alternated across days in a superordinate multielement design. Results indicate that (a) the behavioral effects of MPH were influenced by one or more of the analogue conditions for each participant, and (b) time-out was associated with zero or near-zero levels of both disruptive and off-task behavior for 3 of the 4 participants during MPH and placebo conditions. Implications for the clinical effectiveness of MPH and possible behavioral mechanisms of action of MPH in applied settings are discussed.  (+info)

Identification and pharmacological characterization of a series of new 1H-4-substituted-imidazoyl histamine H3 receptor ligands. (2/610)

A new series of 1H-4-substituted imidazole compounds were synthesized and identified as potent and selective histamine (HA) H3 receptor ligands. These ligands establish that HA H3 antagonists exhibit stereoselective and conformational preferences in their binding to the HA H3 receptor. Structure-activity relationships were determined in vitro by HA H3 receptor-binding affinities using [3H]Nalpha-methylhistamine and rat cerebral cortical tissue homogenates. Several derivatives containing olefin, amide, and acetylene functional groups were identified as potent HA H3 receptor ligands. In the olefin series, GT-2227 (4-(6-cyclohexylhex-cis-3-enyl)imidazole) was identified as a potent HA H3 receptor ligand with a Ki of 4.2 +/- 0.6 nM, while the trans isomer (GT-2228) displayed a reduced potency (Ki = 15.2 +/- 2.4 nM). GT-2227 was also found to have excellent central nervous system penetration in an ex vivo binding paradigm (ED50 = 0.7 mg/kg i.p.). In the acetylene series, GT-2260 and GT-2286 both exhibited high affinity (Ki = 2.9 +/- 0.2 and 0.95 +/- 0.3 nM) and excellent central nervous system penetration profiles (ED50 = 0.43 and 0.48 mg/kg i.p., respectively). As a prototype for the series, GT-2227 showed high affinity for the human HA H3 receptor (3.2 nM) and minimal affinity for the human HA H1 (Ki = 13,407 +/- 540 nM) and H2 (Ki = 4,469 +/- 564 nM) receptor subtypes. GT-2227 also showed good selectivity for the HA H3 receptor over a broad spectrum of other neurotransmitter receptors (IC50 >/= 1 microM). Furthermore, GT-2227 improved acquisition in a cognitive paradigm without behavioral excitation or effect on spontaneous locomotor activity. In summary, the present studies demonstrate the development of novel HA H3-selective ligands, and lend support for the use of such agents in the treatment of disorders associated with cognitive or attentional deficits.  (+info)

Comparative pharmacokinetics and tissue distribution of the d-enantiomers of para-substituted methylphenidate analogs. (3/610)

A comparative study of the plasma pharmacokinetics and tissue distribution of the d-threo enantiomers of methylphenidate (MPH), para-bromomethylphenidate (p-Br MPH), and para-methoxymethylphenidate (p-OCH3 MPH) was conducted in rats after i.p. administration of a 37 micromol/kg dose. The plasma kinetic data was fit to a two-compartment model with absorption and lag time as well as evaluated by noncompartmental methods. All three compounds attained maximal concentration within 10 min of injection. Calculated mean residence time and elimination half-life values for d-p-Br MPH were significantly longer than those for d-MPH and d-p-OCH3 MPH, and clearance of the bromo derivative was substantially lower than the latter two compounds. Tissue distribution studies of the three d-threo enantiomers revealed that para-substitution of d-MPH had a profound effect on the distribution pattern of these drugs. The highest concentration of drug was found in the kidney and lung for d-MPH, lung and liver for d-p-Br MPH, and lung and brain for d-p-OCH3 MPH. The bromo derivative was found in the highest concentration in the central nervous system at 30, 120, and 180 min whereas levels of d-MPH were twice as high as d-p-OCH3 MPH at 30 min but slightly lower than the latter at 120 min. Related studies on the lipophilicity, plasma protein binding, and resistance to plasma degradation of these compounds were also conducted. The combined data from these experiments along with the pharmacokinetics and central nervous system distribution of these drugs provide explanations for discrepancies between the in vivo and in vitro activity of these compounds described in previous work.  (+info)

Effect of methylphenidate on attention in children with attention deficit hyperactivity disorder (ADHD): ERP evidence. (4/610)

Methylphenidate is the most common treatment for attention deficit hyperactivity disorder (ADHD) and has been shown to improve attention and behaviour. However, the precise nature of methylphenidate on specific aspects of attention at different dose levels remains unclear. We studied methylphenidate effects in ADHD from a neurophysiological perspective, recording event-related potentials (ERPs) during attention task performance in normal controls and children with ADHD under different dose conditions. Twenty children with ADHD and 20 age matched controls were assessed with a continuous performance task requiring subjects to identify repeating alphabetic characters. ERPs and behavioural measures were recorded and analyzed for trials where a correct response was made. The ADHD group was assessed off drug (baseline) and on placebo, low (0.28 mg/kg) and high (0.56 mg/kg) dose levels of methylphenidate. The results showed that the ADHD group at baseline was more impulsive and inattentive than controls and had shorter P2 and N2 latencies and longer P3 latencies. Low dose methylphenidate was associated with reduced impulsivity (fewer false alarms) and decreased P3 latencies, whereas the higher dose level was associated with reduced impulsivity and less inattention (more hits), as well as increased P2 and N2 latencies and decreased P3 latencies. Amplitudes were unaffected and there were no adverse effects of the higher dose for any of the children. These results suggest differential dosage effects and a dissociation between dose levels and aspects of processing.  (+info)

Reproducibility of repeated measures of endogenous dopamine competition with [11C]raclopride in the human brain in response to methylphenidate. (5/610)

The measure of changes in synaptic dopamine (DA) concentration in response to the psychostimulant drug methylphenidate (MP) has been used as an indicator of responsiveness of the DA system. The purpose of this study was to assess the reproducibility of these measures. METHODS: Seven healthy subjects were scanned with PET and [11C]raclopride twice in the same day: 7 min after placebo or methylphenidate (0.5 mg/kg) administration. In parallel we also measured the physiologic and behavioral responses to placebo and to methylphenidate. The same procedures were repeated 1-2 wk later to assess test-retest reproducibility. RESULTS: Measures of plasma to brain transfer constant (K1), striatal distribution volume (DVstr) and DA D2 receptor availability (Bmax/Kd), for the placebo condition were similar for the first (E1) and second (E2) evaluations (Bmax/Kd, E1: 2.77+/-0.44; E2: 2.97+/-0.44). MP administration did not change K1, but it significantly decreased DVstr (E1: -25.9%+/-8.7%, P < or = 0.0002; E2: -20.7%+/-11.7%, P < or = 0.007) and Bmax/Kd (E1: -18.4%+/-8.7%, P < or = 0.002; E2: -13.4%+/-9.2%, P < or = 0.008), and the magnitude of these changes, though lower for E2, did not differ significantly. MP increased pulse rate (E1: +64%+/-43%, P < or = 0.002; E2: +69%+/-33%, P < or = 0.001), systolic pressure (E1: +37%+/-19%, P < or = 0.0006; E2: +29%+/-15%, P < or = 0.0009), self reports for drug effects (0: nothing to 10: extreme) of "rush" (E1: +8+/-3, P < or = 0.0004; E2: +6+/-4, P < or = 0.01) and "high" (E1: +8+/-3, P < or = 0.0001, E2: +8+/-3, P < or = 0.0003), anxiety (E1: +5+/-4, P < or = 0.02; E2: +4+/-4, P = 0.1) and restlessness (E1: +4+/-4, P < or = 0.04; E2: +4+/-5, P = 0.1). The magnitude of the cardiovascular and behavioral effects did not differ between E1 and E2. CONCLUSION: MP-induced changes in striatal DV and in Bmax/Kd, as well as the behavioral and cardiovascular effects, were reproducible with repeated administration.  (+info)

Escalating dose-binge treatment with methylphenidate: role of serotonin in the emergent behavioral profile. (6/610)

Our previous studies indicate that exposure of rats to an escalating-dose, multibinge pattern of amphetamine or methamphetamine administration results in a unique emergent behavioral profile and concomitant regionally specific dopamine response patterns in the nucleus accumbens and caudate-putamen. In the present study, we explored the generality of these effects by using an escalating-dose, multibinge treatment with methylphenidate (MP), a stimulant that, unlike the amphetamines, produces no increase in serotonin transmission. Furthermore, MP exerts many of its effects through dopamine uptake blockade, in contrast to the amphetamines that primarily release dopamine. The results showed that MP administered according to an escalating-dose, multibinge regimen produced the expression of the emergent behavioral profile. This pattern of behavior was also evident in these animals in response to 2.5 mg/kg acute amphetamine after the last MP binge exposure. Consistent with previous evidence, neither acute nor multibinge MP treatment produced a significant serotonin response. In contrast, a regionally specific dopamine response alteration was observed during the course of this treatment. Caudate-putamen dopamine exhibited a pattern of increasing response during an acute MP binge but pronounced tolerance developed to this effect after multiple binges. By contrast, the nucleus accumbens dopamine response did not significantly change during the acute binge and exhibited a slight incremental pattern to the injections of the final binge. These findings, along with the effects of other stimulants, are discussed in terms of a possible role for serotonin and for the differential changes in the caudate-putamen and nucleus accumbens dopamine responses in the emergent behavioral profile. The similarity between the effects of MP and the amphetamines provides further support for the multibinge-induced behavioral profile as a possible animal model for stimulant-induced psychosis.  (+info)

Reinforcing effects of psychostimulants in humans are associated with increases in brain dopamine and occupancy of D(2) receptors. (7/610)

Increases in dopamine concentration in limbic brain regions have been postulated to underlie the reinforcing effects of psychostimulant drugs in laboratory animals. However, neither the qualitative nor the quantitative relationship between drug-induced increases in brain dopamine and the reinforcing effects of psychostimulant drugs have been investigated in humans. Positron emission tomograph and [(11)C]raclopride, a dopamine D(2) receptor radioligand that competes with endogenous dopamine for occupancy of the D(2) receptors, were used to measure changes in brain dopamine after different doses of i.v. methylphenidate in 14 healthy controls. In parallel, measures for self-reports of drug effects were obtained to assess their relationship to methylphenidate-induced changes in brain dopamine. The intensity of the "high" induced by methylphenidate was significantly correlated with the levels of released dopamine (r = 0.78, p <.001); subjects having the greatest increases were those who perceived the most intense high. This relationship remained significant after partialing out for dose and concentration of methylphenidate in plasma. Furthermore, subjects for whom methylphenidate did not increase dopamine did not perceive a high. These results represent the first clear demonstration that stimulant-induced high, a mood descriptor that reflects reinforcing effects of drugs in humans, is associated with increases in brain dopamine, and also that there is a quantitative relationship between levels of D(2) receptor occupancy by dopamine and the intensity of the high.  (+info)

Enantioselective gas chromatography-negative ion chemical ionization mass spectrometry for methylphenidate in human plasma. (8/610)

Therapeutic doses of Ritalin, a racemic mixture of d- and l-threo-methyphenidate, result in low plasma concentrations of methylphenidate. In order to assess the safety and efficacy of methylphenidate, a sensitive analytical method is needed. A gas chromatography-negative ion chemical ionization mass spectrometry (GC-NCI-MS) assay capable of measuring both d- and l-enantiomers in human plasma was developed and validated to support clinical studies involving administration of d,l-methylphenidate. d,l-Methylphenidate-d3 is added to 1-mL plasma samples. The plasma samples are made basic, mixed with isopropanol and extracted with hexane. The hexane extracts are then back-extracted into 0.1 N HCl. The acidified aqueous extract is made basic, cooled to ice temperature, and the methylphenidate derivatized with heptafluorobutyryl-l-prolyl chloride. The two diastereomeric derivatives are then extracted into hexane. The hexane extract is evaporated to dryness, reconstituted in ethyl acetate, and analyzed by GC-NCI-MS. This method can accurately (+/- 5% target) and precisely (< 11.1% coefficient of variation) quantitate enantiomers of threo-methylphenidate in human plasma and in the whole blood at concentrations ranging from 0.75 to 100 ng/mL. Plasma samples are stable for up to five freeze-thaw cycles when the duration of each cycle did not exceed 0.5 h. The drug degraded gradually when plasma samples were left at room temperature; a 6% loss at 3 h progressed to 17% at 12 h and to 35% at 24 h. Therefore, it is important that extraction of plasma samples begins within 0.5 h after samples are removed from the freezer. Whole blood stability results show that concentrations of methylphenidate in whole blood, with or without NaF, stored for up to 6 h at room temperature did not deviate from the target concentration by more than 13%. The derivatized methylphenidate in extract is stable at 4 degrees C for up to 10 days.  (+info)

Methylphenidate is a central nervous system (CNS) stimulant drug that is primarily used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It works by increasing the levels of neurotransmitters, such as dopamine and norepinephrine, in the brain, which helps to improve focus, concentration, and alertness.

Methylphenidate is available under various brand names, including Ritalin, Concerta, and Methylin, among others. It comes in different forms, such as tablets, capsules, or extended-release formulations, and is typically taken orally. The dosage and duration of treatment are usually individualized based on the patient's response to the medication and any potential side effects.

It is important to note that methylphenidate has a high potential for abuse and addiction, and its use should be closely monitored by a healthcare professional. Additionally, it can interact with other medications and medical conditions, so it is essential to inform your doctor of any health concerns before starting treatment with methylphenidate.

Central nervous system (CNS) stimulants are a class of drugs that increase alertness, attention, energy, and/or mood by directly acting on the brain. They can be prescribed to treat medical conditions such as narcolepsy, attention deficit hyperactivity disorder (ADHD), and depression that has not responded to other treatments.

Examples of CNS stimulants include amphetamine (Adderall), methylphenidate (Ritalin, Concerta), and modafinil (Provigil). These medications work by increasing the levels of certain neurotransmitters, such as dopamine and norepinephrine, in the brain.

In addition to their therapeutic uses, CNS stimulants are also sometimes misused for non-medical reasons, such as to enhance cognitive performance or to get high. However, it's important to note that misusing these drugs can lead to serious health consequences, including addiction, cardiovascular problems, and mental health issues.

Attention Deficit Hyperactivity Disorder (ADHD) with hyperactivity is a neurodevelopmental disorder that affects both children and adults. The condition is characterized by symptoms including:

1. Difficulty paying attention or staying focused on a single task
2. Impulsivity, or acting without thinking
3. Hyperactivity, or excessive fidgeting, restlessness, or talking

In order to be diagnosed with ADHD with hyperactivity, an individual must exhibit these symptoms to a degree that is developmentally inappropriate and interferes with their daily functioning. Additionally, the symptoms must have been present for at least six months and be present in multiple settings (e.g., at home, school, work).

It's important to note that ADHD can manifest differently in different people, and some individuals may experience predominantly inattentive or impulsive symptoms rather than hyperactive ones. However, when the hyperactive component is prominent, it is referred to as ADHD with hyperactivity.

Effective treatments for ADHD with hyperactivity include a combination of medication (such as stimulants) and behavioral therapy. With appropriate treatment, individuals with ADHD can learn to manage their symptoms and lead successful, fulfilling lives.

Propylamines are a class of organic compounds characterized by the presence of a propylamine group, which is a functional group consisting of a propyl chain (-C3H7) attached to an amino group (-NH2). Propylamines can be primary, secondary, or tertiary, depending on the number of organic substituents attached to the nitrogen atom.

In a medical context, propylamines may refer to certain drugs that contain this functional group and have pharmacological activity. For example, some local anesthetics, such as procaine (Novocain), are derivatives of propylamine. Procaine is a ester of p-aminobenzoic acid and diethylaminoethanol, where the amino group is part of a propylamine chain.

It's important to note that not all compounds containing propylamines have medical applications or uses, as this functional group can also be found in various chemicals with different properties and applications.

Dopamine uptake inhibitors are a class of medications that work by blocking the reuptake of dopamine, a neurotransmitter, into the presynaptic neuron. This results in an increased concentration of dopamine in the synapse, leading to enhanced dopaminergic transmission and activity.

These drugs are used in various medical conditions where dopamine is implicated, such as depression, attention deficit hyperactivity disorder (ADHD), and neurological disorders like Parkinson's disease. They can also be used to treat substance abuse disorders, such as cocaine addiction, by blocking the reuptake of dopamine and reducing the rewarding effects of the drug.

Examples of dopamine uptake inhibitors include:

* Bupropion (Wellbutrin), which is used to treat depression and ADHD
* Methylphenidate (Ritalin, Concerta), which is used to treat ADHD
* Amantadine (Symmetrel), which is used to treat Parkinson's disease and also has antiviral properties.

It's important to note that dopamine uptake inhibitors can have side effects, including increased heart rate, blood pressure, and anxiety. They may also have the potential for abuse and dependence, particularly in individuals with a history of substance abuse. Therefore, these medications should be used under the close supervision of a healthcare provider.

Dopamine plasma membrane transport proteins, also known as dopamine transporters (DAT), are a type of protein found in the cell membrane that play a crucial role in the regulation of dopamine neurotransmission. They are responsible for the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron, thereby terminating the signal transduction of dopamine and regulating the amount of dopamine available for further release.

Dopamine transporters belong to the family of sodium-dependent neurotransmitter transporters and are encoded by the SLC6A3 gene in humans. Abnormalities in dopamine transporter function have been implicated in several neurological and psychiatric disorders, including Parkinson's disease, attention deficit hyperactivity disorder (ADHD), and substance use disorders.

In summary, dopamine plasma membrane transport proteins are essential for the regulation of dopamine neurotransmission by mediating the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron.

Adrenergic uptake inhibitors are a class of medications that work by blocking the reuptake of neurotransmitters, such as norepinephrine and dopamine, into the presynaptic neuron. This results in an increase in the amount of neurotransmitter available to bind to postsynaptic receptors, leading to an enhancement of adrenergic transmission.

These medications are used in the treatment of various medical conditions, including depression, attention deficit hyperactivity disorder (ADHD), and narcolepsy. Some examples of adrenergic uptake inhibitors include:

* Tricyclic antidepressants (TCAs): These medications, such as imipramine and amitriptyline, were developed in the 1950s and are used to treat depression, anxiety disorders, and chronic pain.
* Selective serotonin-norepinephrine reuptake inhibitors (SNRIs): These medications, such as venlafaxine and duloxetine, were developed in the 1990s and are used to treat depression, anxiety disorders, and chronic pain.
* Norepinephrine-dopamine reuptake inhibitors (NDRIs): These medications, such as bupropion, are used to treat depression and ADHD.

It's important to note that these medications can have side effects and should be used under the supervision of a healthcare provider.

Dextroamphetamine is a central nervous system stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It works by increasing the levels of certain neurotransmitters, such as dopamine and norepinephrine, in the brain. Dextroamphetamine is available as a prescription medication and is sold under various brand names, including Adderall and Dexedrine. It is important to use this medication only as directed by a healthcare professional, as it can have potentially serious side effects if used improperly.

I couldn't find a medical definition specifically for "delayed-action preparations." However, in the context of pharmacology, it may refer to medications or treatments that have a delayed onset of action. These are designed to release the active drug slowly over an extended period, which can help to maintain a consistent level of the medication in the body and reduce the frequency of dosing.

Examples of delayed-action preparations include:

1. Extended-release (ER) or controlled-release (CR) formulations: These are designed to release the drug slowly over several hours, reducing the need for frequent dosing. Examples include extended-release tablets and capsules.
2. Transdermal patches: These deliver medication through the skin and can provide a steady rate of drug delivery over several days. Examples include nicotine patches for smoking cessation or fentanyl patches for pain management.
3. Injectable depots: These are long-acting injectable formulations that slowly release the drug into the body over weeks to months. An example is the use of long-acting antipsychotic injections for the treatment of schizophrenia.
4. Implantable devices: These are small, biocompatible devices placed under the skin or within a body cavity that release a steady dose of medication over an extended period. Examples include hormonal implants for birth control or drug-eluting stents used in cardiovascular procedures.

Delayed-action preparations can improve patient compliance and quality of life by reducing dosing frequency, minimizing side effects, and maintaining consistent therapeutic levels.

Amphetamine is a central nervous system stimulant drug that works by increasing the levels of certain neurotransmitters (chemical messengers) in the brain, such as dopamine and norepinephrine. It is used medically to treat conditions such as attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity, due to its appetite-suppressing effects.

Amphetamines can be prescribed in various forms, including tablets, capsules, or liquids, and are available under several brand names, such as Adderall, Dexedrine, and Vyvanse. They are also known by their street names, such as speed, uppers, or wake-ups, and can be abused for their euphoric effects and ability to increase alertness, energy, and concentration.

Long-term use of amphetamines can lead to dependence, tolerance, and addiction, as well as serious health consequences, such as cardiovascular problems, mental health disorders, and malnutrition. It is essential to use amphetamines only under the supervision of a healthcare provider and follow their instructions carefully.

Hyperkinesis is not considered a formal medical diagnosis. However, the term is often used informally to refer to a state of excessive or involuntary muscle movements. It is sometimes used as a synonym for hyperkinetic movement disorders, which are a group of neurological conditions characterized by an excess of involuntary movements. Examples of hyperkinetic movement disorders include chorea, dystonia, tics, myoclonus, and stereotypies.

It is important to note that the term "hyperkinesis" is not used in the current diagnostic classifications such as the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) or the International Classification of Diseases (ICD-10). Instead, specific movement disorders are diagnosed and classified based on their underlying causes and symptoms.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Dopamine is a type of neurotransmitter, which is a chemical messenger that transmits signals in the brain and nervous system. It plays several important roles in the body, including:

* Regulation of movement and coordination
* Modulation of mood and motivation
* Control of the reward and pleasure centers of the brain
* Regulation of muscle tone
* Involvement in memory and attention

Dopamine is produced in several areas of the brain, including the substantia nigra and the ventral tegmental area. It is released by neurons (nerve cells) and binds to specific receptors on other neurons, where it can either excite or inhibit their activity.

Abnormalities in dopamine signaling have been implicated in several neurological and psychiatric conditions, including Parkinson's disease, schizophrenia, and addiction.

A cross-over study is a type of experimental design in which participants receive two or more interventions in a specific order. After a washout period, each participant receives the opposite intervention(s). The primary advantage of this design is that it controls for individual variability by allowing each participant to act as their own control.

In medical research, cross-over studies are often used to compare the efficacy or safety of two treatments. For example, a researcher might conduct a cross-over study to compare the effectiveness of two different medications for treating high blood pressure. Half of the participants would be randomly assigned to receive one medication first and then switch to the other medication after a washout period. The other half of the participants would receive the opposite order of treatments.

Cross-over studies can provide valuable insights into the relative merits of different interventions, but they also have some limitations. For example, they may not be suitable for studying conditions that are chronic or irreversible, as it may not be possible to completely reverse the effects of the first intervention before administering the second one. Additionally, carryover effects from the first intervention can confound the results if they persist into the second treatment period.

Overall, cross-over studies are a useful tool in medical research when used appropriately and with careful consideration of their limitations.

The double-blind method is a study design commonly used in research, including clinical trials, to minimize bias and ensure the objectivity of results. In this approach, both the participants and the researchers are unaware of which group the participants are assigned to, whether it be the experimental group or the control group. This means that neither the participants nor the researchers know who is receiving a particular treatment or placebo, thus reducing the potential for bias in the evaluation of outcomes. The assignment of participants to groups is typically done by a third party not involved in the study, and the codes are only revealed after all data have been collected and analyzed.

Raclopride is not a medical condition but a drug that belongs to the class of dopamine receptor antagonists. It's primarily used in research and diagnostic settings as a radioligand in positron emission tomography (PET) scans to visualize and measure the distribution and availability of dopamine D2 and D3 receptors in the brain.

In simpler terms, Raclopride is a compound that can be labeled with a radioactive isotope and then introduced into the body to track the interaction between the radioligand and specific receptors (in this case, dopamine D2 and D3 receptors) in the brain. This information can help researchers and clinicians better understand neurochemical processes and disorders related to dopamine dysfunction, such as Parkinson's disease, schizophrenia, and drug addiction.

It is important to note that Raclopride is not used as a therapeutic agent in clinical practice due to its short half-life and the potential for side effects associated with dopamine receptor blockade.

"Motor activity" is a general term used in the field of medicine and neuroscience to refer to any kind of physical movement or action that is generated by the body's motor system. The motor system includes the brain, spinal cord, nerves, and muscles that work together to produce movements such as walking, talking, reaching for an object, or even subtle actions like moving your eyes.

Motor activity can be voluntary, meaning it is initiated intentionally by the individual, or involuntary, meaning it is triggered automatically by the nervous system without conscious control. Examples of voluntary motor activity include deliberately lifting your arm or kicking a ball, while examples of involuntary motor activity include heartbeat, digestion, and reflex actions like jerking your hand away from a hot stove.

Abnormalities in motor activity can be a sign of neurological or muscular disorders, such as Parkinson's disease, cerebral palsy, or multiple sclerosis. Assessment of motor activity is often used in the diagnosis and treatment of these conditions.

Pemoline is a central nervous system stimulant that was used in the treatment of attention deficit hyperactivity disorder (ADHD). It is a carbamate derivative and its mechanism of action is thought to be related to its ability to increase the levels of dopamine, a neurotransmitter, in the brain. However, due to concerns about liver toxicity, pemoline was withdrawn from the market in many countries including the United States. It's important to note that Pemoline should only be used under the supervision of a physician and it's not commonly used or recommended anymore.

'Animal behavior' refers to the actions or responses of animals to various stimuli, including their interactions with the environment and other individuals. It is the study of the actions of animals, whether they are instinctual, learned, or a combination of both. Animal behavior includes communication, mating, foraging, predator avoidance, and social organization, among other things. The scientific study of animal behavior is called ethology. This field seeks to understand the evolutionary basis for behaviors as well as their physiological and psychological mechanisms.

Apathy is a lack of feeling, emotion, interest, or concern about something. In medical terms, it's often described as a loss of motivation or a decreased level of enthusiasm or concern for activities or events that one would normally care about. Apathy can be a symptom of various medical and neurological conditions, such as depression, dementia, traumatic brain injury, or Parkinson's disease. It can also be a side effect of certain medications. If severe or persistent, it can significantly impact a person's quality of life and ability to function in daily activities.

A placebo is a substance or treatment that has no inherent therapeutic effect. It is often used in clinical trials as a control against which the effects of a new drug or therapy can be compared. Placebos are typically made to resemble the active treatment, such as a sugar pill for a medication trial, so that participants cannot tell the difference between what they are receiving and the actual treatment.

The placebo effect refers to the phenomenon where patients experience real improvements in their symptoms or conditions even when given a placebo. This may be due to psychological factors such as belief in the effectiveness of the treatment, suggestion, or conditioning. The placebo effect is often used as a comparison group in clinical trials to help determine if the active treatment has a greater effect than no treatment at all.

Methamphetamine is a powerful, highly addictive central nervous system stimulant that affects brain chemistry, leading to mental and physical dependence. Its chemical formula is N-methylamphetamine, and it is structurally similar to amphetamine but has additional methyl group, which makes it more potent and longer-lasting.

Methamphetamine exists in various forms, including crystalline powder (commonly called "meth" or "crystal meth") and a rocklike form called "glass." It can be taken orally, snorted, smoked, or injected after being dissolved in water or alcohol.

Methamphetamine use leads to increased levels of dopamine, a neurotransmitter responsible for reward, motivation, and reinforcement, resulting in euphoria, alertness, and energy. Prolonged use can cause severe psychological and physiological harm, including addiction, psychosis, cardiovascular issues, dental problems (meth mouth), and cognitive impairments.

Cocaine is a highly addictive stimulant drug derived from the leaves of the coca plant (Erythroxylon coca). It is a powerful central nervous system stimulant that affects the brain and body in many ways. When used recreationally, cocaine can produce feelings of euphoria, increased energy, and mental alertness; however, it can also cause serious negative consequences, including addiction, cardiovascular problems, seizures, and death.

Cocaine works by increasing the levels of dopamine in the brain, a neurotransmitter associated with pleasure and reward. This leads to the pleasurable effects that users seek when they take the drug. However, cocaine also interferes with the normal functioning of the brain's reward system, making it difficult for users to experience pleasure from natural rewards like food or social interactions.

Cocaine can be taken in several forms, including powdered form (which is usually snorted), freebase (a purer form that is often smoked), and crack cocaine (a solid form that is typically heated and smoked). Each form of cocaine has different risks and potential harms associated with its use.

Long-term use of cocaine can lead to a number of negative health consequences, including addiction, heart problems, malnutrition, respiratory issues, and mental health disorders like depression or anxiety. It is important to seek help if you or someone you know is struggling with cocaine use or addiction.

Norepinephrine plasma membrane transport proteins, also known as norepinephrine transporters (NET), are membrane-bound proteins that play a crucial role in the regulation of neurotransmission. They are responsible for the reuptake of norepinephrine from the synaptic cleft back into the presynaptic neuron, thereby terminating the signal transmission and preventing excessive stimulation of postsynaptic receptors.

The norepinephrine transporter is a member of the sodium-dependent neurotransmitter transporter family and functions as an antiporter, exchanging one intracellular sodium ion for two extracellular sodium ions along with the transport of norepinephrine. This sodium gradient provides the energy required for the active transport process.

Dysregulation of norepinephrine plasma membrane transport proteins has been implicated in various neurological and psychiatric disorders, such as attention deficit hyperactivity disorder (ADHD), depression, and post-traumatic stress disorder (PTSD). Therefore, understanding the function and regulation of these transporters is essential for developing novel therapeutic strategies to treat these conditions.

Respiratory alkalosis is a medical condition that occurs when there is an excess base (bicarbonate) and/or a decrease in carbon dioxide in the body. This leads to an increase in pH level of the blood, making it more alkaline than normal. Respiratory alkalosis is usually caused by conditions that result in hyperventilation, such as anxiety, lung disease, or high altitude. It can also be caused by certain medications and medical procedures. Symptoms of respiratory alkalosis may include lightheadedness, confusion, and tingling in the fingers and toes. Treatment typically involves addressing the underlying cause of the condition.

Sorbose is not a medical term itself, but it is a chemical compound that has been used in the field of medicine and biochemistry. Sorbose is a sugar alcohol, also known as a polyol, which is a type of carbohydrate. It is a stereoisomer of mannitol and D-glucose, and it can be found in some fruits and fermented products.

In medicine, sorbose has been used as a sweetening agent and a pharmaceutical excipient, which is an inactive substance that serves as a vehicle or medium for a drug. It has also been studied for its potential use in the treatment of various medical conditions, such as diabetes and obesity, due to its low caloric content and slow absorption rate.

However, it's important to note that sorbose is not widely used in modern medicine, and its therapeutic benefits have not been fully established through clinical trials. Therefore, it should not be considered a standard treatment for any medical condition without further research and medical supervision.

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.

Nomifensine is a medication that was previously used in the treatment of depression, but it is no longer available in many countries due to safety concerns. It is a non-tricyclic antidepressant that works by inhibiting the reuptake of dopamine and noradrenaline, which helps to increase the levels of these neurotransmitters in the brain and improve mood.

The medical definition of Nomifensine is:

"Nomifensine is a non-tricyclic antidepressant that is a potent inhibitor of dopamine and noradrenaline reuptake, with minimal effects on serotonin reuptake. It was used in the treatment of depression but has been withdrawn from the market due to safety concerns."

It's important to note that Nomifensine should only be taken under the supervision of a medical professional, and it is not available in many countries due to its potential for causing serious side effects such as liver toxicity and the risk of developing a rare but potentially fatal condition called hemolytic anemia.

Self-administration, in the context of medicine and healthcare, refers to the act of an individual administering medication or treatment to themselves. This can include various forms of delivery such as oral medications, injections, or topical treatments. It is important that individuals who self-administer are properly trained and understand the correct dosage, timing, and technique to ensure safety and effectiveness. Self-administration promotes independence, allows for timely treatment, and can improve overall health outcomes.

Operant conditioning is a type of learning in which behavior is modified by its consequences, either reinforcing or punishing the behavior. It was first described by B.F. Skinner and involves an association between a response (behavior) and a consequence (either reward or punishment). There are two types of operant conditioning: positive reinforcement, in which a desirable consequence follows a desired behavior, increasing the likelihood that the behavior will occur again; and negative reinforcement, in which a undesirable consequence is removed following a desired behavior, also increasing the likelihood that the behavior will occur again.

For example, if a child cleans their room (response) and their parent gives them praise or a treat (positive reinforcement), the child is more likely to clean their room again in the future. If a child is buckling their seatbelt in the car (response) and the annoying buzzer stops (negative reinforcement), the child is more likely to buckle their seatbelt in the future.

It's important to note that operant conditioning is a form of learning, not motivation. The behavior is modified by its consequences, regardless of the individual's internal state or intentions.

Stereotyped behavior, in the context of medicine and psychology, refers to repetitive, rigid, and invariant patterns of behavior or movements that are purposeless and often non-functional. These behaviors are not goal-directed or spontaneous and typically do not change in response to environmental changes or social interactions.

Stereotypies can include a wide range of motor behaviors such as hand flapping, rocking, head banging, body spinning, self-biting, or complex sequences of movements. They are often seen in individuals with developmental disabilities, intellectual disabilities, autism spectrum disorder, and some mental health conditions.

Stereotyped behaviors can also be a result of substance abuse, neurological disorders, or brain injuries. In some cases, these behaviors may serve as a self-soothing mechanism or a way to cope with stress, anxiety, or boredom. However, they can also interfere with daily functioning and social interactions, and in severe cases, may cause physical harm to the individual.

Neurofeedback, also known as neurobiofeedback or EEG biofeedback, is a type of biofeedback that involves measuring brain waves and providing that information to the individual in real-time so that they can learn to modify their brain wave activity. It typically involves the use of sensors placed on the scalp that measure electrical activity in the brain, which is displayed to the person in the form of visual or auditory feedback. Through this process, individuals can learn to voluntarily regulate their brain wave activity, with potential applications in the treatment of various neurological and psychiatric conditions such as attention deficit hyperactivity disorder (ADHD), epilepsy, migraines, anxiety disorders, and insomnia.

Biogenic monoamines are a type of neurotransmitter, which are chemical messengers that transmit signals in the brain and other parts of the nervous system. They are called "biogenic" because they are derived from biological substances, and "monoamines" because they contain one amine group (-NH2) and are derived from the aromatic amino acids: tryptophan, tyrosine, and phenylalanine.

Examples of biogenic monoamines include:

1. Serotonin (5-hydroxytryptamine or 5-HT): synthesized from the amino acid tryptophan and plays a crucial role in regulating mood, appetite, sleep, memory, and learning.
2. Dopamine: formed from tyrosine and is involved in reward, motivation, motor control, and reinforcement of behavior.
3. Norepinephrine (noradrenaline): also derived from tyrosine and functions as a neurotransmitter and hormone that modulates attention, arousal, and stress responses.
4. Epinephrine (adrenaline): synthesized from norepinephrine and serves as a crucial hormone and neurotransmitter in the body's fight-or-flight response to stress or danger.
5. Histamine: produced from the amino acid histidine, it acts as a neurotransmitter and mediates allergic reactions, immune responses, and regulates wakefulness and appetite.

Imbalances in biogenic monoamines have been linked to various neurological and psychiatric disorders, such as depression, anxiety, Parkinson's disease, and schizophrenia. Therefore, medications that target these neurotransmitters, like selective serotonin reuptake inhibitors (SSRIs) for depression or levodopa for Parkinson's disease, are often used in the treatment of these conditions.

Exploratory behavior refers to the actions taken by an individual to investigate and gather information about their environment. This type of behavior is often driven by curiosity and a desire to understand new or unfamiliar situations, objects, or concepts. In a medical context, exploratory behavior may refer to a patient's willingness to learn more about their health condition, try new treatments, or engage in self-care activities. It can also refer to the behaviors exhibited by young children as they explore their world and develop their cognitive and motor skills. Exploratory behavior is an important aspect of learning and development, and it can have a positive impact on overall health and well-being.

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