BRAIN BLOOD-FLOW AND EXTRACEREBRAL CAROTID CIRCULATION DURING SLEEP IN RAT

Cerebral blood flow (CBF) and blood flow (BF) in extracerebral head st ructures were measured during the sleep-wake cycle in rats using radio active microspheres. While no statistically significant changes occurr ed in the transition from Waking to quiet sleep (also referred to as s ynchronized or non-REM Sleep), CBF increased significantly in active s leep (AS, also referred to as desynchronized or REM Sleep) in all stru ctures considered, with the sole exception of the cerebellum. In extra cerebral head structures, no significant state-dependent BF changes we re found. Factor Analysis however extracted a common factor accounting for BF variability in the external carotid circulation. This factor w as uncorrelated with CBF changes in AS, suggesting independent regulat ion of the two vascular beds in this sleep state.