Date of Graduation
Eberly College of Arts and Sciences
Karen G. Anderson.
It is well established in animal research that the hypothalamic-pituitary-adrenal (HPA) axis plays a central mediating role in the detrimental effects of prenatal stress in mother and offspring. The prenatally stressed (PS) rat exhibits a number of behaviors indicative of increased HPA activity relative to control (CON) rats. Because of these behaviors, PS rats may learn novel responses more quickly than CON rats. However, there are mixed findings in the literature as to whether prenatal stress facilitates or impedes learning. Experiment 1 was designed to examine effects of prenatal stress on lever-press acquisition using 10-s delays to food pellet delivery in rats. Because of the paucity of literature on the link between stress and impulsive choice, Experiment 2 was designed to assess effects of prenatal stress on delay discounting (impulsive choice) in rats. Previous research has demonstrated that increased stress is correlated with greater facilitation and maintenance of drug taking. There is also evidence that increased rates of delay discounting are correlated with increased drug taking. Experiment 3 was designed to assess effects of prenatal stress on ethanol self-administration in rats. The present set of studies is the first to investigate the variables of stress, delay discounting, and ethanol self-administration using a within-subject design. During Experiment 1, PS rats obtained significantly more food pellets and responded at a higher rates on the lever correlated with food than CON rats. Prenatal stress did not differentially affect impulsive choice (Experiment 2) or ethanol consumption (Experiment 3). As is consistent with past research, a negative correlation was found between indifference points and g/kg of ethanol consumed for the lowest ethanol concentration during the two-bottle choice test. Lower indifference points (i.e., greater impulsivity) were correlated with greater g/kg of ethanol consumed for one of the testing concentrations.
Bruner, Natalie R., "Effects of prenatal stress on lever-press acquisition, delay discounting, and ethanol self -administration in rats" (2010). Graduate Theses, Dissertations, and Problem Reports. 3082.