Long-term behavioral and developmental consequences of pre- and perinatal nicotine

Abstract

Research has shown that cigarette use during pregnancy can result in increased fetal mortality, sudden infant death syndrome, and behavioral and attentional disorders during childhood. Neurochemical and behavioral consequences of prenatal nicotine exposure have been well documented although few studies have examined long-term behavioral consequences that persist into adulthood. In this study, fifty-eight male and female Long-Evans rats were exposed to chronic nicotine prenatally and postnatally via subcutaneous infusions (0.96 mg/kg/day) in the dam. Nicotine exposure continued in the pups via maternal milk until the dams' osmotic mini-pumps became exhausted at approximately postnatal day (P) 11. At weaning, animals were group housed until behavioral testing at P60 to assess spatial learning and memory in the Morris water maze (MWM). Mild deficits in spatial learning were observed in nicotine-exposed females. These behavioral differences were accompanied by significant reduction in weight gain of nicotine-exposed females beginning at puberty, suggesting a hormonal interaction. Long-term effects of nicotine exposure were less striking in males. Nicotine-exposed males had significantly slower swim speeds than controls, but latency to reach the hidden platform was equal between groups by the conclusion of testing. Weight gain in males did not differ between groups as a result of prenatal nicotine exposure.