[S-35]-GTP gamma S autoradiography reveals alpha(2) adenoceptor-mediated G-protein activation in amygdala and lateral septum

alpha(2)-adrenoceptor-mediated G-protein activation was examined by [S-35]- GTP gamma S autoradiography. In alpha(2)-adrenoceptor-rich regions (amygdal a, lateral septum), noradrenaline stimulated [S-35]-GTP gamma S binding. Th ese actions were abolished by the selective alpha(2) antagonist, atipamezol e. Conversely, in caudate nucleus, which expresses few alpha(2) receptors, noradrenaline-induced stimulation was not inhibited by atipamezole, suggest ing that it is not mediated by alpha(2)-adrenoceptors. (C) 2000 Elsevier Sc ience Ltd. All rights reserved.