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Head-twitch Response
The head-twitch response (HTR) is a rapid side-to-side head movement that occurs in mice and rats after the serotonin 5-HT2A receptor is activated. The prefrontal cortex may be the neuroanatomical locus mediating the HTR. Many serotonergic hallucinogens, including lysergic acid diethylamide (LSD), induce the head-twitch response, and so the HTR is used as a behavioral model of hallucinogen effects. However while there is generally a good correlation between compounds that induce head twitch in mice and compounds that are hallucinogenic in humans, it is unclear whether the head twitch response is primarily caused by 5-HT2A receptors, 5-HT2C receptors or both, though recent evidence shows that the HTR is mediated by the 5-HT2A receptor and modulated by the 5-HT2C receptor. Also, the effect can be non-specific, with head twitch responses also produced by some drugs that do not act through 5-HT2 receptors, such as phencyclidine, yohimbine, atropine and cannabinoid receptor antagonists. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction. Approximately 90% of the serotonin that the body produces is in the intestinal tract. Biochemically, the indoleamine molecule derives from the amino acid tryptophan, via the (rate-limiting) hydroxylation of the 5 position on the ring (forming the intermediate 5-hydroxytryptophan), and then decarboxylation to produce serotonin. Serotonin is primarily found in the enteric nervous system located in the gastrointestinal tract (GI tract). However, it is also produced in the central nervous system (CNS), specifically in the raphe nuclei located in the brainstem, Merkel cells located in the skin, pulmonary neuroendocrine cells and taste receptor cells in the tongue. Additionally, serotonin is stored in blood platelets and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2A Receptor
The 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor (GPCR). The 5-HT2A receptor is a cell surface receptor, but has several intracellular locations. 5-HT is short for 5-hydroxy-tryptamine or serotonin. This is the main excitatory receptor subtype among the GPCRs for serotonin, although 5-HT2A may also have an inhibitory effect on certain areas such as the visual cortex and the orbitofrontal cortex. This receptor was first noted for its importance as a target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. Later it came back to prominence because it was also found to be mediating, at least partly, the action of many antipsychotic drugs, especially the atypical ones. Downregulation of post-synaptic 5-HT2A receptor is an adaptive process provoked by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. Suicidal and otherwis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefrontal Cortex
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, and BA47. The basic activity of this brain region is considered to be orchestration of thoughts and actions in accordance with internal goals. Many authors have indicated an integral link between a person's will to live, personality, and the functions of the prefrontal cortex. This brain region has been implicated in executive functions, such as planning, decision making, short-term memory, personality expression, moderating social behavior and controlling certain aspects of speech and language. Executive function relates to abilities to differentiate among conflicting thoughts, determine good and bad, better and best, same and different, future consequences of current activities, working toward a defined goal, prediction of outcomes, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysergic Acid Diethylamide
Lysergic acid diethylamide (LSD), also known colloquially as acid, is a potent psychedelic drug. Effects typically include intensified thoughts, emotions, and sensory perception. At sufficiently high dosages LSD manifests primarily mental, visual, as well as auditory, hallucinations. Dilated pupils, increased blood pressure, and increased body temperature are typical. Effects typically begin within half an hour and can last for up to 20 hours. LSD is also capable of causing mystical experiences and ego dissolution. It is used mainly as a recreational drug or for spiritual reasons. LSD is both the prototypical psychedelic and one of the "classical" psychedelics, being the psychedelics with the greatest scientific and cultural significance. LSD is typically either swallowed or held under the tongue. It is most often sold on blotter paper and less commonly as tablets, in a watery solution or in gelatin squares called panes. LSD is considered to be non-addictive with low potent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2C Receptor
The 5-HT2C receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). It is a G protein-coupled receptor (GPCR) that is coupled to Gq/G11 and mediates excitatory neurotransmission. ''HTR2C'' denotes the human gene encoding for the receptor, that in humans is located at the X chromosome. As males have one copy of the gene and in females one of the two copies of the gene is repressed, polymorphisms at this receptor can affect the two sexes to differing extent. Structure At the cell surface the receptor exists as a homodimer. The crystal structure is known since 2018. Distribution 5-HT2C receptors are located mainly in the choroid plexus, and in rats is also found in many other brain regions in high concentrations, including parts of the hippocampus, anterior olfactory nucleus, substantia nigra, several brainstem nuclei, amygdala, subthalamic nucleus and lateral habenula. 5-HT2C receptors are also found on epithel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phencyclidine
Phencyclidine or phenylcyclohexyl piperidine (PCP), also known as angel dust among other names, is a dissociative anesthetic mainly used recreationally for its significant mind-altering effects. PCP may cause hallucinations, distorted perceptions of sounds, and violent behavior. As a recreational drug, it is typically smoked, but may be taken by mouth, snorted, or injected. It may also be mixed with cannabis or tobacco. Adverse effects may include seizures, coma, addiction, and an increased risk of suicide. Flashbacks may occur despite stopping usage. Chemically, PCP is a member of the arylcyclohexylamine class, and pharmacologically, it is a dissociative anesthetic. PCP works primarily as an NMDA receptor antagonist. PCP is most commonly used in the United States. While usage peaked in the US in the 1970s, between 2005 and 2011 an increase in visits to emergency departments as a result of the drug occurred. As of 2017 in the United States, about 1% of people in Twelfth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yohimbine
Yohimbine (), also known as quebrachine, is an indole alkaloid derived from the bark of the African tree ''Pausinystalia johimbe''; also from the bark of the unrelated South American tree ''Aspidosperma quebracho-blanco''. Yohimbine is an α2-adrenergic receptor antagonist, and has been used in a variety of research projects. It is a veterinary drug used to reverse sedation in dogs and deer. While yohimbine behaves as an aphrodisiac in some mammals, it does not do so in humans. It has been prescribed as a treatment for erectile dysfunction, although its reported clinical benefits were modest and it has largely been superseded by the PDE5 inhibitor class of drugs. Substances that have purported to be extracts from the yohimbe tree have been marketed as dietary supplements for various purposes, but they contain highly variable amounts of yohimbine, if any; no published scientific evidence supports their efficacy. Uses Yohimbine is a drug used in veterinary medicine to reverse th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atropine
Atropine is a tropane alkaloid and anticholinergic medication used to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate, and to decrease saliva production during surgery. It is typically given intravenously or by injection into a muscle. Eye drops are also available which are used to treat uveitis and early amblyopia. The intravenous solution usually begins working within a minute and lasts half an hour to an hour. Large doses may be required to treat some poisonings. Common side effects include a dry mouth, large pupils, urinary retention, constipation, and a fast heart rate. It should generally not be used in people with angle closure glaucoma. While there is no evidence that its use during pregnancy causes birth defects, that has not been well studied. It is likely safe during breastfeeding. It is an antimuscarinic (a type of anticholinergic) that works by inhibiting the parasympathetic nervous system. Atropine occurs n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannabinoid Receptor Antagonist
A cannabinoid receptor antagonist, also known simply as a cannabinoid antagonist or as an anticannabinoid, is a type of cannabinoidergic drug that binds to cannabinoid receptors (CBR) and prevents their activation by endocannabinoids. They include antagonists, inverse agonists, and antibodies of CBRs. The discovery of the endocannabinoid system led to the development of CB1 receptor antagonists. The first CBR inverse agonist, rimonabant, was described in 1994. Rimonabant blocks the CB1 receptor selectively and has been shown to decrease food intake and regulate body-weight gain. The prevalence of obesity worldwide is increasing dramatically and has a great impact on public health. The lack of efficient and well-tolerated drugs to cure obesity has led to an increased interest in research and development of CBR antagonists. Cannabidiol (CBD), a naturally occurring cannabinoid, is a non-competitive CB1/CB2 receptor antagonist. And Δ9-tetrahydrocannabivarin (THCV), a naturally occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HTP
5-Hydroxytryptophan (5-HTP), also known as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin. Uses 5-HTP is sold over the counter in the United States, Canada, Singapore, the Netherlands, and the United Kingdom as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under the trade names Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. A 2002 review concluded that although the data evaluated suggests that 5-HTP is more effective than placebo in the treatment of depression, the evidence was insufficient to be conclusive due to a lack of clinical data meeting the rigorous standards of the day. More and larger studies using current methodologies are needed to determine if 5-HTP is truly effective in treating depression. In small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fenfluramine
Fenfluramine, sold under the brand name Fintepla, is a serotonergic medication used for the treatment of seizures associated with Dravet syndrome and Lennox–Gastaut syndrome.https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/212102s003lbl.pdf It was formerly used as an appetite suppressant in the treatment of obesity, but was discontinued for this use due to cardiovascular toxicity before being repurposed for new indications. Fenfluramine was used for weight loss both alone under the brand name Pondimin and in combination with phentermine under the brand name Fen-Phen among others. Side effects of fenfluramine in people treated for seizures include decreased appetite, somnolence, sedation, lethargy, diarrhea, constipation, abnormal echocardiogram, fatigue, malaise, asthenia, ataxia, balance disorder, gait disturbance, increased blood pressure, drooling, excessive salivation, fever, upper respiratory tract infection, vomiting, appetite loss, weight loss, falls, and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-Methylpsilocin
1-Methylpsilocin is a tryptamine derivative which acts as a selective agonist for the 5-HT2C receptor (IC50 of 12 nM, vs 633 nM at 5-HT2A), and an inverse agonist at 5-HT2B (Ki of 38 nM). While 1-methylpsilocin does have higher affinity for 5-HT2C than 5-HT2A, it does produce a head-twitch response in mice that are dependent on 5-HT2A, so it is not entirely free of effects on 5-HT2A in vivo. In contrast to psilocin, 1-methylpsilocin did not activate 5-HT1A receptors in mice. 1-Methylpsilocin has been investigated for applications such as treatment of glaucoma, OCD, and cluster headaches, as these conditions are amenable to treatment with psychedelic drugs but are not generally treated with such agents due to the hallucinogenic side effects they produce, which are considered undesirable. 1-Methylpsilocin therefore represents a potential alternative treatment to psilocin that may be less likely to produce hallucinogenic effects. See also * 2-Bromo-LSD * CP-1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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