Response to Deep Brain Stimulation in the Lateral Hypothalamic Area in a Rat Model of Obesity: In Vivo Assessment of Brain Glucose Metabolism

To investigate changes in glucose brain metabolism after deep brain stimulation (DBS) in the lateral hypothalamic area (LHA) in a rat model of obesity. Ten obese male Zucker rats were divided into two groups: LHA-control and LHA-DBS. Concentric bipolar platinum-iridium electrodes were implanted bilaterally. After 7 days, DBS was applied for 15 days. Weight and food and water intake were monitored. 2-Deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) PET-CT imaging studies were performed the day after the end of DBS. Differences in glucose uptake between the groups were assessed with statistical parametric mapping. A difference in weight gain of 3.19 percentage points was found between groups. Average food consumption during the first 15 days was lower in DBS-treated animals than in non-stimulated animals. DBS increased metabolism in the mammillary body, subiculum-hippocampal area, and amygdala, while a decrease in metabolism was recorded in the thalamus, caudate, temporal cortex, and cerebellum. DBS produced significant changes in brain regions associated with the control of food intake and the brain reward system. DBS seems to normalize the impaired hippocampal functioning that has been described in obese rats. The smaller weight gain in the DBS group suggests that this technique could be considered an option for the treatment of obesity.