Interactive effects of chronic maternal ethanol and nicotine exposure upon offspring development and function.

Nicotine injections (3.0 mg/kg twice daily), oral alcohol (10% solution), nicotine and alcohol, or saline injections were administered to gravid Sprague-Dawley rats for the entire gestational period. Food intake was adjusted so that all rats received the same number of calories on each day of pregnancy. Offspring performance was monitored from birth to 15 months of age. An interaction was found in which the combined effect of nicotine and alcohol was greater than would have been predicted from the effects of either drug along. NIC/ALC offspring were born later, and suffered more stillbirths and neonatal deaths. Surviving NIC/ALC offspring were more advanced on some developmental measures, more active neonatally and less active in adulthood. Initially, they were able to discriminate contingencies less well in a punishment paradigm, initiated fewer shock-on periods and received fewer reinforcements. Possible mechanisms for the drug interaction effects are discussed.