Microinfusion of cocaine into the medial preoptic area or nucleus accumbens transiently impairs maternal behavior in the rat

Cocaine was microinfused bilaterally (50 mu g/0.5 mu l/side) into the media l preoptic area (MPOA) or nucleus accumbens (NA), 2 regions within the rat brain neural circuit known to mediate maternal behavior (MB). Additionally, 2 sites not involved in this neural circuit, the dorsal striatum and dorsa l medial hippocampus. were used as control sites. Microinfusion of cocaine into the MPOA or NA impaired MB, whereas infusion into the control sites di d not. MB impairment was not temporally coincident with the increased locom otor activity, also documented after cocaine infusion into the MPOA or NA, arguing strongly that impaired IMB is a direct, specific effect of cocaine in these areas, not a derivative of increased motor activity. This is the f irst demonstration that cocaine action on single central nervous system (CN S) sites can impair MB to the same extent as systemic injections. Thus, coc aine's simultaneous effect on multiple CNS sites is not required for MB imp airment.