ANTIDEPRESSANT ANXIOLYTIC IPSAPIRONE INHIBITS COLD-INDUCED HYPOTHALAMIC TRH RELEASE

ACUTE administration of the serotonin (5-HT)1A receptor agonist ipsapi rone has been previously shown to elicit a dose-dependent decrease of cold-elicited thyrotropin (TSH) secretion. Therefore, the aim of the p resent study was to evaluate, by means of a push-pull cannula implante d in the median eminence (ME), whether ipsapirone acts primarily throu gh an inhibition of cold-elicited thyrotropin-releasing hormone (TRH) release. Ipsapirone administration (10 mg kg-1 i.p., 30 min before col d) prevented cold-elicited TRH release, thereby confirming the above h ypothesis. In addition, this study further validates push-pull perfusi on in the ME as a key tool for measuring TRH secretion in vivo.