Serotonin 1A and 2A receptors - PET Studies in Anorexia and Bulimia nervosa

Several lines of evidence suggest that individuals with bulimia nervosa (BN) and anorexia nervosa (AN) have persistent disturbances of brain serotonin (5-HT) neurotransmission after recovery. The 5-HT1a and 5-HT2a receptor system is of particular interest in AN and BN because this receptor has been implicated in feeding and mood modulation as well as response to antidepressant medication (acting on 5-HT system). This application will apply new technologies with the potential for increased understanding of previously inaccessible brain neurotransmitter function and its dynamic relationship with human behaviors. We will use Positron Emission Tomography (PET) imaging with the selective radioligand (Carbonyl-11C)WAY100635 to assess regional binding of 5HT1a receptor and the selective radioligand [18F]altanserin to assess regional binding of 5-HT2a receptor because disturbances of these receptors could contribute to behavioral disturbances in AN and BN. Altered functional activity of these receptors may serve to confirm that a dysfunction of 5-HT neuronal activity persists after recovery. We hypothesize that women recovered from AN or BN have increased 5-HT1a and decreased 5- HT2a binding compared to healthy controls. This application will therefore study women ages 18 to 45 years old who are: 1) recovered from bulimia nervosa (recovery is defined as>1 year normal menses, no bingeing and purging, and healthy and stable weight) (n=15); 2) recovered from bulimia-type anorexia nervosa (n=5) and 3) healthy control women (CW) (n=10). These data may be of heuristic value in devising new treatment interventions for this often chronic and relapsing disorders.