Monoamine oxidase and head-twitch response in mice. Mechanisms of alpha-methylated substrate derivatives.
It is well known that head-twitch response (HTR) in mice represents hallucinations, since administration of lysergic acid diethylamide (LSD) produces hallucinations in humans, and the HTR in mice is induced by administration of LSD as a hallucinogen. The HTR is produced by excitation of 5-hydroxytryptamine (5-HT)2A receptors. In this paper, we review the mechanisms of HTR induced by various drugs such as 5-HT precursor, 5-HT receptor agonist, 5-HT releaser, hallucinogenic compounds, benzodiazepins and cannabinoid. The response induced by HTR-inducers is significantly enhanced by combined treatment with a non-selective form of monoamine oxidase (MAO) inhibitor. Thus, the relationship between MAO activity and HTR caused by these drugs (especially, alpha-methylated analogous compounds which 5-fluoro-alpha-methyltryptamine, 6-fluoro-alpha-methyltryptamine and p-hydroxyamphetamine) is presented in detail.
Nakagawasai
Osamu
O
Department of Pharmacology, Tohoku Pharmaceutical University, Sendai 981-8558, Japan. osamun@tohoku-pharm.ac.jp
Arai
Yuichiro
Y
Satoh
Shin-etsu
SE
Satoh
Nobunori
N
Neda
Mitsuro
M
Hozumi
Masato
M
Oka
Ryusho
R
Hiraga
Hajime
H
Tadano
Takeshi
T
D000818:Animals; D004357:Drug Synergism; D006212:Hallucinations / Q000139:chemically induced* / Q000201:enzymology; D019416:Head Movements / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D011985:Receptors, Serotonin / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000737:chemistry / Q000494:pharmacology; D014363:Tryptamines / Q000737:chemistry / Q000494:pharmacology
D008996:Monoamine Oxidase Inhibitors; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D014363:Tryptamines; C015293:indopan; D008995:Monoamine Oxidase