Effects of neonatal cocaine exposure on two measures of balance and coordination

This study examined the effects of third trimester cocaine exposure on motor coordination and balance using a rodent model. The subjects were Sprague-Dawley rats that had been artificially reared (AR) and fed through gastrostomy tubes from postnatal days (PND 4-11). The AR groups included two groups given either 20 mg/kg/day or 60 mg/kg/day cocaine hydrochloride and a control group. A suckled control group raised by its natural dam was also included to control for artificial rearing. In Experiment 1, neonatal exposure to the high dose of cocaine resulted in impaired performance on parallel rods at 19-21 days of age. Exposure to the lower dose of cocaine impaired parallel rod performance on 20 and 21 days of age. In Experiment 2, walking gait was examined in 38-48-day-old subjects. Neonatal cocaine exposure was associated with a narrower stance width, however, there were no differences across neonatal treatment groups on step angle or stride length. These data suggest that third trimester cocaine exposure results in balance and coordination impairments. These findings support preliminary data suggesting motor impairments in infants with prenatal cocaine histories.