Moderate stimuli will cause an increase in synaptosomal glutamate and choline uptake in the hippocampus, septum, frontal cortex, and basal ganglia of the rat. These increases occur after serum increases in endogenous corticosteroids. Consequently, the role of corticosteroids in modulating this brain change is of interest. Experiments with adrenalectomized rats, dexamethasone-challenged rats, and in vitro preparations suggest that glucocorticoids do not play a role in stimuli-related changes in glutamate uptake.
