DIFFERENTIAL-EFFECTS OF PRENATAL COCAINE AND RETINOIC ACID ON ACTIVITY LEVEL THROUGHOUT DAY AND NIGHT

Prenatal cocaine exposure is associated with disrupted state control a nd lowered activity levels. Prenatal retinoic acid excess also influen ces activity levels in laboratory rats. Activity level is usually moni tored during a brief period in young offspring. The effects of these d rugs on pup activity levels throughout the day is unknown. There is al so little information on the long-lasting effects of these teratogens in adult animals. We compared the daily activity of rats which were pr enatally exposed to cocaine or retinoic acid (RA). Appropriate control groups were also used. The offspring were evaluated for activity leve ls in a neophobic situation and for a 22-h period in same-sex groups o f 3 littermates. As both pups and adults, the cocaine groups were hypo active while the RA group was hyperactive when first placed into the t esting cage (neophobic situation). Similarly, during the remainder of the 22-h testing period, the pup and adult cocaine animals exhibited r educed activity levels while the RA animals exhibited elevated activit y levels. Thus, prenatal cocaine and retinoic acid exposures affected offspring activity levels differently, both drugs have longlasting neu robehavioral effects that persist into adulthood, and effects are infl uenced by time-of-day. Strain-dependent differences and mechanisms of action are discussed. Copyright (C) 1996 Elsevier Science Inc.