Abstract:
Early environmental and behavioral experiences can affect development during
adolescence and even adulthood. Prenatal effects can result in lasting changes on the
nervous system and behavior. Gestational stress has been shown to lead to an increased
vulnerability to substance abuse and addiction disorders. Exposure to stress is associated
with sensitive periods of vulnerability that also uniquely contributes to drug abuse
vulnerability. Compulsive drug use can increase due to a highly reactive HPA-axis,
which can be dysregulated by prenatal stress exposure (Andersen & Teicher, 2009).
While the results of studies done with other drugs of abuse suggest that animals exposed
to prenatal stress are more vulnerable to substance abuse, the effects of prenatal stress on
nicotine exposure is unknown, particularly on initial nicotine experiences during
adolescence. Indeed, research on the effects of prenatal stress on adolescent behavior and
development is scarce. As adolescence is the most common age for initial nicotine use,
and as adolescence is a sensitive period where reinforcing effects of nicotine are stronger
than in adults, we carried out an experiment to determine the effects of prenatal stress on
adolescent nicotine reward using a rat model. The conditioned place preference (CPP)
paradigm, widely used to assess the rewarding effects of abused drugs in rodents [Bardo
& Bevins, 2000], is ideal for modeling initial responsivity to nicotine. In this experiment,
pregnant female rats underwent either restraint stress [45 min 3X daily, P14-P21], or no
stress. Adolescent male offspring underwent a four-day, single-trial nicotine CPP
procedure in a conditioning apparatus consisting of 2 distinct sides. The results show that
prenatal stress altered the posttest time of nicotine place preference in adolescence. This
suggests the prenatal stress may actually be acting on anxiety and that could be altering
the conditioned place preference results.
