Abstract
Hyperactivity of the hypothalamicβpituitaryβadrenal (HPA) axis is a marked feature of anorexia nervosa. Using a modified version of the activityβbased animal model of anorexia nervosa, we examine whether factors known to affect HPA axis activity influence the development of activityβbased anorexia (ABA). Male and female rats were subjected to maternal separation or handling procedures during the first two postnatal weeks and tested in a mild version of the ABA paradigm, comprised of 2βhr daily running wheel access followed by 1βhr food access, either in adolescence or adulthood. Compared to handled females, maternally separated females demonstrated greater increases in wheel running and a more pronounced runningβinduced suppression of food intake during adolescence, but not in adulthood. In contrast, it was only in adulthood that wheel running produced more prolonged anorexic effects in maternally separated than in handled males. These findings highlight the interplay between early postnatal treatment, sex of the animal, and developmental age on running, food intake, and rate of body weight loss in a mild version of the ABA paradigm. Β© 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 679β695, 2009.