Do functional relationships exist between 5-HT1A and 5-HT2 receptors?
Pharmacology, biochemistry, and behavior – August 01, 1990
Source: PubMed
Summary
A compelling finding reveals that the 5-HT2 receptor agonist (+/-)-DOI triggers head-twitch behavior in mice, with the (-)-DOI isomer being twice as potent as the (+) variant. In a dose-dependent manner, selective 5-HT2 antagonists like ketanserin and spiperone effectively inhibited this response. Additionally, both nonselective and 5-HT1A-selective agonists reduced head-twitching, while the 5-HT1B/5-HT1C-selective agonist (TFMPP) had no effect. This suggests that 5-HT1A receptors may inhibit responses mediated by 5-HT2 receptors when activated by (+/-)-DOI.
Abstract
To investigate the possible functional relationship between 5-HT1 and 5-HT2 receptors, we studied the effects of a nonselective 5-HT agonist (5-MeO DMT), a 5-HT1A-selective (8-OH-DPAT) and a 5-HT1B/5-HT1C-selective (TFMPP) agonist on the head-twitch behavior induced by the putative 5-HT2-selective receptor agonist (+/-)-DOI. In the mouse (+/-)-DOI produced the head-twitch response in a dose-dependent manner and (-)-DOI was twice as potent as the (+) isomer. Selective 5-HT2 antagonists, ketanserin and spiperone, dose-dependently inhibited the (+/-)-DOI-induced head-twitch response. The nonselective and the 5-HT1A-selective agonists also dose-dependently reduced the behavior, whereas 5-HT1B/5-HT1C-selective agonist (TFMPP) failed to affect the (+/-)-DOI-induced response. Taken together with previously published literature data, we propose a 5-HT1A inhibitory action on the 5-HT2 receptor-mediated response when induced by its selective agonist (+/-)-DOI.