MODULATION OF THE GABA_A RECEPTOR BY SRIF IN RAT THALAMUS

Abstract

Somatostatin has been reported to modulate GABA A receptor complex in many brain structures. This study was conducted to investigate somatostatin modulation of the GABA A receptor binding in several rat diencephalic structures, focusing primarily on the thalamus, as this structure plays important roles. Animals were assigned to control conditions. Changes in specific binding of GABA A receptor as labelled with [35 S]tButylbicyclophosphorothionate (TBPS) were assessed by in vitro quantitative autoradiography with the aid of a computer assisted image analysis system. Our results reveal the presence of higher densities in several thalamic structures located principally in the part of thalamus. We demonstrate for the first time the presence of a modulatory effect of somatostatin on the GABA A receptor complex in this brain region in rats. Indeed, the peptide affected in a concentration-dependent manner; the binding of