Relative cerebral glucose uptake of neuronal perikarya and neuropil determined with 2-deoxyglucose in resting and swimming rat

An autoradiographic method using tracer amounts of [¹⁴C]-2-deoxy-d-glucose (2-DG) was used to detect areas of the brain in which glucose consumption was altered in swimming as compared to resting rats. Areas in which changes occurred in the swimming rat were widespread in gray matter, being greatest in the cerebellar vermis and least in portions of the cerebellar hemispheres and the inferior colliculi. Improved resolution was obtained with an autoradiographic method for [³H]-2-DG. The number of grains per unit area over neuronal perikarya was either slightly greater or equal to that over the immediately surrounding neuropil in both resting and swimming rats. This indicated that the glucose consumption of neuronal perikarya and the immediately surrounding neuropil per unit volume were similar. Since gray matter is composed predominantly of neuropil, the present results indicate that the bulk of the total brain gray matter glucose consumption is accounted for by neuropil in both the resting and swimming states.