Skip to content

Opposite effects of intraventricular serotonin and bufotenin on rat startle responses.

Mark A. Geyer, J D Warbritton, D B Menkes, John A. Zook, Arnold J. Mandell

Pharmacology, biochemistry, and behavior 1975 DOI: 10.1016/0091-3057(75)90193-8 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Experimental study Peer reviewed
Population Rats
Interventions 5-hydroxytrptamine (5-HT) 5-hydroxy-N saline
Topics Serotonin
Citations 34
Key findings 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.