Opposite effects of intraventricular serotonin and bufotenin on rat startle responses.
M A Geyer, J D Warbritton, D B Menkes, J A Zook, A J Mandell
Pharmacology, biochemistry, and behavior January 1, 1975 DOI: 10.1016/0091-3057(75)90193-8 via PubMed
Summary
AI-generated from the abstractRat startle responses to air puffs were measured during infusion of serotonin (5-HT), a hallucinogenic compound (5-HDMT), or saline. Serotonin reduced startle magnitude in a dose-dependent way, while the hallucinogen increased startle responses. Neither compound specifically affected sensitization or habituation. The findings suggest a central serotonin system that promotes behavioral inhibition, which indoleamine hallucinogens may oppose.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Rats |
| Interventions | 5-hydroxytrptamine (5-HT) 5-hydroxy-N saline |
| Citations | 34 |
| Key finding | Serotonin decreased startle responses dose-dependently, while the hallucinogen 5-HDMT increased startle magnitude, with no specific effects on sensitization or habituation. |
Abstract
Rat startle responses to air puffs were monitored in a stabilimeter during the intraventricular infusion of various doses of 5-hydroxytrptamine (5-HT) or the putative hallucinogenic congener of 5-HT, 5-hydroxy-N, N-dimethyltrytamine (5-HDMT) or saline. Qualitativity opposite effects were observed, with 5-HT producing a dose-dependent decrease in responsivity and 5-HDMT increasing the magnitude of startle responses. No specific effects of either compound could be demonstrated on the presumably separable processes of sensitization and habituation. The results are discussed in the context of a central serotonergic system which facilitates behavioral inhibition and which is antagonized by indoleamine hallucinogens.