Cerebral energy metabolism during the onset and recovery from halothane anesthesia

Halothane (1%) was administered to twenty-two gram female Swiss-Albino mice which were sacrificed at times of 15 seconds, 45 seconds, 79 seconds and 5 minutes. Additional animals were exposed for 5 minutes and sacrificed 10 minutes after removal from halothane (recovery). Selected energy metabolites were measured in 100-500 nanogram samples from the inferior colliculus and the ascending reticular activating system. Results from this study showed an increase in glucose levels at 79 seconds, when the animals first lost their righting response. The glucose increase was similar in the inferior colliculus and reticular formation. ATP and phosphocreatine were increased at 45 seconds, and during the sleep period in the ascending reticular activating system, and returned to normal during the recovery period. In the inferior colliculus. ATP was similarly increased from 45 seconds throughout the time course, whereas phosphocreatine was elevated at 79 seconds, and during recovery only. These data suggest a decrease in utilization of energy metabolites during halothane anesthesia, both in cells of the inferior colliculus and ascending reticular activating system.