MicroPET imaging in an animal model of anorexia nervosa

Anorexia nervosa is a life-threatening psychiatric disorder characterized by severe weight loss and high rates of comorbidity and mortality. The current study assessed the feasibility of using microPET imaging to study the effects of chronic food restriction in an animal model of anorexia nervosa. To establish preliminary support for this model, we hypothesized that chronic food restriction would decrease relative 2-deoxy-2-[18F]fluoro-D-glucose (18FDG) uptake in the rat, in effect modeling cerebral glucose hypometabolism reported in the clinical population of anorexia nervosa. Nine adolescent Wistar female rats received a baseline 18FDG scan. The control group received free access to food for a period of 25 days. The food restricted (FR) group received 40% of their baseline daily food intake until a 30% weight loss occurred; body weight was then maintained at 70% of baseline by adjusting daily food intake. The FR group also had free access to a running wheel for a mean period of 10.8+/-6.1 days. Both groups received a follow-up 18FDG scan. Relative 18FDG uptake was significantly increased in the cerebellum and significantly decreased in the hippocampus and striatum in the FR group compared to controls. Moreover, there was a trend towards a decrease in relative 18FDG uptake in the thalamus in the FR compared to control group. This is the first study to establish support for the use of microPET imaging in an animal model of anorexia nervosa as a means for studying the neurobiological changes that occur due to chronic food restriction.