Selective attenuation of cocaine-induced stereotyped behaviour by oxytocin: putative role of basal forebrain target sites.

The effects of oxytocin (OXT), arginine- and lysine-vasopressin (AVP and LVP) and an OXT-receptor antagonist on cocaine-induced sniffing behaviour were investigated in rats. OXT, but not AVP or LVP injected subcutaneously (s.c.) attenuated cocaine-induced sniffing. The effect of OXT (s.c.) was inhibited by an OXT-receptor antagonist administered intracerebroventricularly (i.c.v.). I.c.v. administration of different doses of OXT in nanogram quantities caused a dose-dependent attenuation of cocaine-induced sniffing. Local cerebral microinjection of OXT into the accumbens nucleus and olfactory tubercle but not into the olfactory nucleus, central amygdaloid nucleus or caudate nucleus, inhibited the cocaine-induced sniffing behaviour. These results demonstrate that OXT selectively attenuates the cocaine-induced stereotyped behaviour through basal forebrain target sites.