Medicine: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.[1] The prefrontal cortex may be the neuroanatomical locus mediating the HTR.[2] 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,[3] 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.[4][5] 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 well, compounds such as 5-HTP, fenfluramine, 1-Methylpsilocin, Ergometrine, and 3,4-di-methoxyphenethylamine (DMPEA) can also produce head twitch and do stimulate serotonin receptors, but are not hallucinogenic in humans.[6][7] This means that while the head twitch response can be a useful indicator as to whether a compound is likely to display hallucinogenic activity in humans, the induction of a head twitch response does not necessarily mean that a compound will be hallucinogenic, and caution should be exercised when interpreting such results.[8]
References
- ↑ "Monoamine oxidase and head-twitch response in mice. Mechanisms of alpha-methylated substrate derivatives". Neurotoxicology 25 (1–2): 223–32. January 2004. doi:10.1016/S0161-813X(03)00101-3. PMID 14697897.
- ↑ "Direct injection of 5-HT2A receptor agonists into the medial prefrontal cortex produces a head-twitch response in rats". The Journal of Pharmacology and Experimental Therapeutics 282 (2): 699–706. August 1997. PMID 9262333.
- ↑ "Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species". Neuropharmacology 167: 107933. May 2020. doi:10.1016/j.neuropharm.2019.107933. PMID 31917152.
- ↑ "Modulation by 5-hT2A receptors of aggressive behavior in isolated mice". Japanese Journal of Pharmacology 89 (1): 89–92. May 2002. doi:10.1254/jjp.89.89. PMID 12083749.
- ↑ "The role of 5-HT2A, 5-HT 2C and mGlu2 receptors in the behavioral effects of tryptamine hallucinogens N,N-dimethyltryptamine and N,N-diisopropyltryptamine in rats and mice". Psychopharmacology 232 (1): 275–84. January 2015. doi:10.1007/s00213-014-3658-3. PMID 24985890.
- ↑ Corne, S. J.; Pickering, R. W. (1967). "A possible correlation between drug-induced hallucinations in man and a behavioural response in mice" (in en). Psychopharmacologia 11 (1): 65–78. doi:10.1007/BF00401509. ISSN 0033-3158. PMID 5302272. http://link.springer.com/10.1007/BF00401509.
- ↑ Shulgin, Alexander; Shulgin, Ann (1991) (in en). PiHKAL: A Chemical Love Story (1st ed.). Transform Press. pp. 614–616. ISBN 978-0-9630096-0-9.
- ↑ "Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model". Drug Testing and Analysis 4 (7–8): 556–76. July 2012. doi:10.1002/dta.1333. PMID 22517680.
 |  |
