Acute cocaine alters oxytocin levels in the medial preoptic area and amygdala in lactating rat dams: implications for cocaine-induced changes in maternal behavior and maternal aggression

Acute cocaine administration has been correlated with disruptions in the on set and maintenance of maternal behavior as well as decreases in maternal a ggressive behavior in rat dams. A growing body of evidence suggests that co caine may alter oxytocin levels leading to impairments in maternal behavior and aggression. The current study assessed whether acute cocaine injection s alter oxytocin (OT) levels in the medial preoptic area (MPOA), ventral te gmental area (VTA), amygdala (AMY), and hippocampus (HIP) on postpartum day (PPD) 1 or PPD 6. On PPD 1, 30 mg/kg cocaine reduced OT levels by approxim ately 26.9% (picograms/milligrams) in the MPOA (t(18) = 3.44, P < .01) comp ared to saline. On PPD 6, 30 mg/kg cocaine significantly increased OT level s by approximately 20.9% (picograms/brain area) in the AMY (F(2,25) = 3.44, P = .05) relative to saline. These findings suggest that acute cocaine may disrupt maternal behavior and maternal aggression at least in part through its action on the oxytocinergic system. (C) 2001 Harcourt Publishers Ltd.