Play behavior and stress responsivity in periadolescent offspring exposed prenatally to cocaine.

Play behavior and stress responsiveness were examined in offspring exposed gestationally to cocaine. The subjects were offspring of Sprague-Dawley rat dams given s.c. injections of 40 mg/kg/3 cc cocaine HC1 daily from gestational days 8-20 (C40), pair-fed dams injected daily with saline (PF), and untreated control dams (LC). Periadolescent (postnatal day (P) 30-36) male and female rats were assigned to either pretest Stress or No Stress conditions. Every other day Stress animals were exposed to a stressor (on P30--foot shock; P32--white noise; P34--forced swim; P36--foot shock), with each stressor being administered 4 h prior to a play session. Immobility during one of the stressors, foot shock, was used to assess stress responsiveness. Play sessions consisted of pairing each experimental animal with a same-sex, nonexperimentally manipulated conspecific for 7 min. The results indicated that periadolescent offspring exposed gestationally to cocaine differed from controls in their stress responsivity, as evidenced by a failure to show increased immobility during the final foot shock session. Also, while cocaine-exposed juveniles did not differ from controls in their own play behavior, these offspring elicited less play solicitation from conspecifics, as evidenced by an increased latency to be pounced, and decreased frequency and duration of being pounced. These findings parallel earlier evidence for altered stress responsiveness in adult cocaine-exposed rats and also suggest that prenatal exposure to cocaine results in altered social cues.