5HT-2 mediation of acute behavioral effects of hallucinogens in rats
Psychopharmacology March 1, 1990 Lauren L. Wing, Gregory S. Tapson, Mark A. Geyer 99 citations
In rats, acute injections of 5HT-2 agonists including mescaline, quipazine, DOI, DOM, and DOET suppressed locomotor and investigatory behavior during the first 30 minutes in a novel environment. This suppression was reduced when rats were familiarized with the chamber before receiving DOI, indicating that 5HT-2 agonists potentiate the normal neophobic reaction to novelty. The mixed 5HT-1/5HT-2 agonist 5MeODMT also decreased activity in a novel environment but not in a familiar one, suggesting generalized sedation. Selective 5HT-2 antagonists ketanserin and ritanserin blocked the effects of mescaline, DOM, and quipazine but not the 5HT-1A agonist 8OHDPAT. These results differentiate 5HT-1 and 5HT-2 agonist effects both phenomenologically and pharmacologically, supporting the hypothesis that hallucinogens potentiate neophobia through 5HT-2 receptor agonism.