The effect of unilateral and bilateral removal of the entorhinal cortex on the glucose utilization in various hippocampal regions in the rat.

In the present study lesion-induced changes in function of various hippocampal regions, as reflected by the metabolic rate of glucose, were measured by means of quantitative autoradiography, 4 days after unilateral or bilateral surgical removal of the entorhinal cortex. The greatest decrease (45%) was seen in the stratum lacunosum moleculare of the CA1, whereas a lesser decline (34%) was seen in the molecular layer of the dentate gyrus, stratum lucidum of the CA3 (31%) and the stratum radiatum of the CA1 (36%). These findings support the view that in addition to the indirect trisynaptic temporo-ammonic pathway, there is a functionally active direct pathway.