PRENATAL COCAINE ALTERS OPEN-FIELD BEHAVIOR IN YOUNG SWINE

Yucatan minisows received 2 mg/kg cocaine IV 4 times daily during the last third of gestation. Their piglets were fostered at birth to paire d, unexposed sows with their litters, and studied at age 2 to 9 (young group) and 22 to 29 days (older group). Three to 5 exposed and unexpo sed piglets of each age group were videotaped together for 30 min on 5 consecutive days in an open-field environment. For each piglet, 41 be haviors were scored, timed, summed and clustered into 9 behavioral cat egories. With age, and independently of drug exposure, piglets spent m ore time in ingestion, immobility while alone and play/aggression, and less time in group locomotion. For the first 4 test days, the young e xposed piglets spent more time in group immobility and less time in in dividual locomotion and rooting than their age-matched controls. In co ntrast, the older exposed and unexposed piglet groups did not differ i n any of these behavioral clusters. These results suggest that prenata l cocaine exposure in neonatal swine may transiently affect responses to spatial novelty.