THE BEHAVIORAL-RESPONSE TO STRESS IS ALTERED IN ADULT-RATS EXPOSED PRENATALLY TO COCAINE

The behaviors displayed during and following acute stress exposure were investigated in rats prenatally exposed to cocaine. Offspring from Sprague-Dawley rat dams given SC injections of 40 mg/kg/3 cc cocaine HCl (C40) daily from gestational days 8-20, pair-fed dams injected daily with saline (PF), and untreated control dams (LC) were examined. Adult male rats 60 days old (P60) from the three prenatal groups were given either a 5-min forced swim test (FS), 10 min of intermittent foot shock exposure, or were not exposed to either acute stressor. Amount of immobility or inactivity during acute stress exposure was recorded. One day later, all animals were given a 5-min open field test. During both of the acute stressors, C40 offspring exhibited significantly less immobility than PF and LC control offspring. Whereas prior foot shock experience enhanced the amount of immobility shown by LC and PF offspring in the open field, similar immobility scores were observed between shocked and nonstressed C40 rats. In contrast, prior foot shock experience reduced locomotion in all prenatal treatment groups. These findings suggest that prenatal cocaine exposure results in altered behavioral reactivity in terms of the immediate and delayed response to stressful experiences.