Comparison of two positive reinforcing stimuli: Pups and cocaine throughout the postpartum period

This set of experiments investigated the appetitive or motivational process es underlying the performance of maternal behavior. The place preference pa radigm was adapted to simultaneously investigate the reinforcing properties of cocaine and pups for maternal. lactating dams. These modifications allo wed the authors to assess which stimulus, either a 10 mg/kg sc injection of cocaine or 3 pups, had the strongest reinforcing value. At Postpartum Days 10 and 16, the dams preferred the cocaine cue-associated chamber. whereas the dams tested at Postpartum Day 8 preferred the pup cue-associated chambe r. Overall, the data revealed an interaction between the postpartum period at testing and the exhibited preference for cocaine or pups. Further testin g will investigate the neural circuitry underlying the appetitive processes of each stimulus.