Nicotine-induced locomotor activity is increased by preexposure of rats toprenatal stress

Genetic factors are believed to play a predominant role in the individual d ifferences observed in behavioral and pharmacological responses to drugs of abuse. An increasing literature indicates, however, that epigenetic factor s can be involved as well. In this report we examined whether developmental changes induced by prenatal stress could alter the way animals respond to the psychostimulant effect of nicotine when adults. The results show that n icotine induces a dose-dependent increase of locomotor activity in both gro ups, and that prenatally-stressed animals exhibit a higher behavioral respo nse at all doses. This study emphasizes the importance of early environment in the later development of drug-related behavior. (C) 2000 Elsevier Scien ce B.V. All rights reserved.