HYPERACTIVITY INDUCED BY PRENATAL NICOTINE EXPOSURE IS ASSOCIATED WITH AN INCREASE IN CORTICAL NICOTINIC RECEPTORS

Prenatal exposure to nicotine may lead to hyperactivity. To evaluate p ossible involvement of central nicotinic receptors in this condition, pregnant Sprague-Dawley rats were implanted with osmotic minipumps to receive nicotine (6 mg/kg/day) or saline throughout gestation. A total of 222 pups (118 males and 104 females) from 24 dams were measured fo r locomotor activity. Male and female hyperactive and nonhyperactive o ffspring from each treatment group were selected and analyzed for nico tinic receptor concentrations in various brain regions. Hyperactive ma le offspring that were prenatally exposed to nicotine exhibited a sign ificant increase in the cortical receptor densities without a change i n binding affinity. Hyperactive offspring of saline-treated darns did not show an increase in cortical nicotinic receptors. These results su ggest that hyperactive male offspring of nicotine-exposed dams are als o susceptible to neurochemical effects of intrauterine nicotine exposu re. (C) 1997 Elsevier Science Inc.