Local cerebral glucose utilization non-selectively elevated in rapid eye movement sleep of the fetus

The [14C]deoxyglucose method for measuring local cerebral glucose utilization was employed in an effort to identify regions of the brain which participate in the increased neuronal activity of rapid eye movement (REM) sleep. The study was conducted in near term fetal sheep in which REM periods are of sufficient duration to obtain reliable data with this method. Neither the postulated executive centers of REM sleep nor those structures in the brainstem known to participate in the electrical activity peculiar to this sleep phase were found to have selectively elevated rates of glucose utilization. Rather, these regions shared equally with virtually all other structures in having rates higher than those which accompany non-REM sleep.