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 onset and maintenance of maternal behavior as well as decreases in maternal aggressive behavior in rat dams. A growing body of evidence suggests that cocaine may alter oxytocin levels leading to impairments in maternal behavior and aggression. The current study assessed whether acute cocaine injections alter oxytocin (OT) levels in the medial preoptic area (MPOA), ventral tegmental 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 approximately 26.9% (picograms/milligrams) in the MPOA (t(18) = 3.44, P < .01) compared to saline. On PPD 6, 30 mg/kg cocaine significantly increased OT levels 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.