Dopamine and serotonin release in the nucleus accumbens during starvation-induced hyperactivity.

Activity-based anorexia (ABA) is considered an animal model for anorexia nervosa (AN). By scheduled feeding and voluntary wheel running, it mimics severe body weight loss and increased physical activity in AN. Pharmacological, genetic and imaging studies implicate dopamine and serotonin in the regulation of feeding behavior, food-anticipatory activity, and food reward. Previous studies propose that the nucleus accumbens (NAc) plays an important role in these food-related processes. Here we determined dopamine and serotonin levels in the NAc upon exposure to the ABA model. Surprisingly, the release of dopamine and serotonin in the NAc were not increased during the initiation of food-anticipatory behavior in ABA rats. Dopamine release in the NAc was increased during feeding behavior in ABA rats. During ABA, levels of serotonin were low and circadian activity is blunted. We conclude that during the early stages of development of food-anticipatory activity, increased dopamine does not trigger hyperactivity.