"The addition of naltrexone alters cerebral glucose uptake following acute forced swimming".

Endogenous opioid release has been linked to exercise. We investigated if opioid blockade following forced swimming, a common model of rodent exercise, influenced cerebral glucose metabolism in mice. PET scan was used to assess the uptake of Fludeoxyglucose (FDG-18), a marker of cerebral glucose metabolism in 19 regions of the interest in the brain following: forced swimming, an acute dose of the opioid receptor blocker naltrexone or a combination of both. Forced swimming increased glucose uptake in the cerebellum, while naltrexone + forced swimming increased glucose uptake in the hypothalamus, forebrain, septum and amygdala. This suggests that opioid blockade alters the typical pattern of cerebral glucose uptake following forced swimming in mice in certain areas of the brain.