Postnatal effects of maternal nicotine exposure.

Rats were given dilute nicotine solutions as their only source of drinking water while control rats received distilled water. Two months after the start of treatment the rats were mated. At birth litters born to nicotine treated rats were either left with the dams until weaning (nicotine group) or cross-fostered to control dams (cross-fostered nicotine group). Both parents and offspring were tested when the pups were 60 to 80 days of age. The drug-treated adult rats showed a marked reduction in body weight gain during the period of drug treatment. The dams were more active during the day and exhibited a reduced plasma corticosterone response to stress. Male but not female offspring of nicotine treated rats were significantly lighter at birth than control males. Offspring in the nicotine group showed an increased spontaneous motor activity in the light which was not prevented by cross-fostering to control dams at birth. The results support the hypothesis that pre-natal exposure to nicotine causes significant changes in behavior in later life.