REGIONAL DIFFERENCES IN NACL-INDUCED INCREASE OF THE POTENCY OF BICUCULLINE TO DISPLACE [H-3] MUSCIMOL BINDING/

It has been shown that the potency of bicuculline to displace [H-3]mus cimol binding to crude brain membranes can be enhanced markedly by dif ferent anions. This study shows that although bicuculline alone was a more potent displacer of [H-3]muscimol binding in cortical than in cer ebellar membranes, the NaCl (250 mM)-induced leftward shift of the bic uculline inhibition curve of [H-3]muscimol binding was considerably hi gher in cerebellum than in cortex. The same concentration of NaCl fail ed to affect either the affinity or the density of cortical and cerebe llar [H-3]muscimol binding sites. The results suggest that sodium chlo ride is able to reveal regional differences in bicuculline potency. Co pyright (C) 1996 Elsevier Science Ltd