NPY Y-1 RECEPTORS IN THE DORSAL PERIAQUEDUCTAL GRAY-MATTER REGULATE ANXIETY IN THE SOCIAL-INTERACTION TEST

WE have reported previously that the NPY Y-1 receptor antagonist BIBP3 226 applied into the dorsal periaqueductal gray matter (DPAG) has an a nxiogenic-like effect in the elevated plus-maze test in rats. In the p resent study the effects of neuropeptide Y (NPY) Y-1 receptor antagoni sts BIBP3226 (500 pmol) and 1229U91 (formerly also GR231118, GW1229 an d EXBP68, 100 and 500 pmol) administered into the DPAG were investigat ed in the social interaction test in rats. BIBP3226 and 1229U91 (both 500 pmol) significantly decreased the time spent in active social inte raction. These results provide additional evidence that NPY-ergic neur otransmission in the DPAG may be involved in the modulation of anxiety -related behaviour and suggest that endogenous NPY, released under str essful conditions in the DPAG, relieves anxiety via the NPY Y-1 recept ors. This is the first report demonstrating the effect of NPY receptor active agent on social behaviour. (C) 1998 Lippincott Williams & Wilk ins.