Correlation of regional brain metabolism with receptor localization during ketamine anesthesia: Combined autoradiographic 2-[³H]deoxy-D-glucose receptor binding technique

LKB film autoradiography of 2-[³H]deoxy-D-glucose uptake shows that ketamine, administered in anesthetic doses, alters the pattern of metabolic activity in rat hippocampus. The labeled metabolic marker can be washed out of the slidemounted tissue sections by preincubation to permit in vitro autoradiography of drug and neurotransmitter receptors in the same animal. In this way, opiate and phencylidine receptor distributions may be correlated with patterns of glucose utilization in adjacent sections. If the observed relative enhancement of 2-deoxy-D-glucose uptake in the stratum moleculare of hippocampus reflects elevated metabolism in nerve terminal there, then the binding of ketamine to phencyclidine receptors on neurons in distant afferent sites, such as entorhinal cortex, may initiate the physiologic and metabolic effects.