Medtronic 4th Neuroscience Fair location:Tolochenaz, Switzerland date:27 February 2009
Anorexia nervosa is a severe and difficult-to-treat psychiatric disorder. For those patients that are treatment-resistant to state-of-the-art interventions, electrical brain stimulation might be a new treatment. However, it is currently unknown in which brain region electrical stimulation induces symptom relief. We use functional neuroimaging and neuromodulation in an animal model for anorexia nervosa to study the neurocircuitry that is involved. In the activity-based anorexia model in rats, food restriction to 1.5h daily in experimental cages equipped with a running wheel leads to an increase in activity and a decrease in food intake and body weight. This behavior has been validated to model some of the symptoms of anorexia nervosa. We demonstrated an increase in regional metabolism in the mediodorsal thalamus, ventral pontine nuclei and cerebellum, and a decrease in metabolism left rhinal and bilateral insular cortex and bilateral ventral striatum in a positron emission tomography study with 18F-fluorodeoxyglucose (van Kuyck et al, Neuroimage). We initially selected brain regions for neuromodulation based on these functional neuroimaging data but only negative results were obtained (e.g. in the mediodorsal thalamus, Luyten, Welkenhuysen, van Kuyck et al, Brain Res Bull). Electrolytic lesions in the nucleus accumbens also had no effect compared to controls. However, two animals with a lesion located outside the nucleus accumbens showed an increase in body weight. At current, neuromodulation studies are performed in this new target.