IS THERE AN ENERGY-CONSERVATION SYSTEM IN BRAIN THAT PROTECTS AGAINSTTHE CONSEQUENCES OF ENERGY DEPLETION

A poorly understood marked decrease (circa 50% of control) in local ce rebral glucose utilization is caused by sublethal doses of NaCN. The d ecrease is global, occurring in essentially all brain regions and is e ntirely reversible within hours, leaving no obvious pathology. This ev ent is not unique to NaCN in so far as a strikingly similar pattern of decreased glucose utilization occurs with some other toxins. Nor can it be attributed to a direct action of NaCN since local application by microdialysis to the striatum produces a global depression. These res ults imply that some widely distributed ''system'' or substance is inv olved. We speculate the existence of a ''system'' possibly related to the reticular activating system that senses a fall in energy productio n and acts globally to make cells quiescent and thus would give some p rotection from excitotoxic driven damage.