VENTRAL MEDULLARY SURFACE-ACTIVITY DURING SLEEP, WAKING, AND ANESTHETIC STATES IN THE GOAT

We examined activity, measured as changes in reflected light, from the surface of a rostral ventral medullary area that is involved in cardi orespiratory control. We collected images during sleep and waking stat es and during halothane anesthesia in live adult unrestrained goats. D uring quiet sleep, overall activity increased and overall variability decreased compared with waking levels, whereas rapid eye movement slee p increased variability, and average activity decreased to near-waking levels. Distinct regions of activation and suppression appeared durin g sleep states. Deep anesthesia decreased activity and minimized varia tion. We speculate that alterations in rostral ventral medullary surfa ce activity may play a role in state-dependent changes in cardiorespir atory control mechanisms.