It is proposed to study specific aspects of acetylcholine (ACh) metabolism in major brain regions of intact mice during hypoglycemic and hypoxic stupor, and during behavioral recovery. The research will focus on three phages: (1) regional CNS glucose, choline, and ACh levels during these conditions, (2) regional CNS ACh turnover during these conditions, and (3) the effect of prior systemic treatment with cholinergic and anticholinergic agents on subsequent behavioral and regional CNS neurochemical responses (ie. choline and ACh levels and ACh turnover) during these conditions. In the first phase, plasma levels of glucose and choline will be measured as well as levels of glucose, choline, and ACh in cerebral cortex, striatum, hippocampus, brainstem, and cerebellum. These substances will be measured in controls, in either hypoglycemic or hypoxic stuporous animals, and in mice during the time of behavioral recovery from stupor. Animals will be sacrificed by focussed microwave irradiation. In the second phase, choline(methyl3H) will be given intravenously to controls, hypoglycemic or hypoxic stuporous animals, and to mice during behavioral recovery. The incorporation of labelled plasma choline into brain choline and ACh will be measured during each of these clinical states. ACh turnover will be calculated. In the third phase, the behavioral and neurochemical effects of atropine, scopolamine, physostigmine, and deanol will be compared. Their ability to modify subsequent behavioral and biochemical responses to hypoglycemia and hypoxia will be tested.