PROBLEM-SOLVING FOLLOWING NEONATAL EXPOSURE TO COCAINE, ETHANOL, OR COCAINE ETHANOL IN COMBINATION IN RATS/

This study examined the effects of neonatal drug exposure on performan ce in a digging maze. Subjects were Sprague-Dawley rats, artificially reared (AR) and fed through a gastrostomy tube from postnatal days (PN D) 4-10. The AR groups included a cocaine group (20 mg/kg/day cocaine hydrochloride), an ethanol group (4 g/kg/day ethanol), a cocaine/ethan ol group (20 mg/kg/day cocaine and 4 g/kg/day ethanol), and an AR cont rol group. A suckled control raised by its dam was also included. At a pproximately PND 55, subjects were tested in a digging maze paradigm. The digging maze required subjects to use a species typical behavior ( digging) to solve a novel problem (gaining access to water). While neo natal treatment had no effect on acquisition of a simple runway task f or water reward, neonatal exposure to cocaine and ethanol in combinati on resulted in impaired performance on the digging maze task. None of the other neonatal treatment groups showed impairments on this task. T hese findings suggest that exposure to these doses of cocaine and etha nol during neonatal development may have more serious effects on probl em solving tasks in rats than exposure to either drug alone.