Quantitative Histochemical Approaches to Energy Metabolism in Nervous Tissue

Abstract

The central nervous system presents a structural complexity which is likely to be reflected by heterogeneity in biochemical function. Even a few milligrammes of brain contain a mixture of nerve and glial cell bodies, axons, dendrites, myelin, glial processes and endothelial cells, intricately related to one another and intertwined. From the clear evidence of radical differences in function among these various structures, we must assume that each has its idiotypic metabolism. Although classical analysis of gross structures or homogenates might be expected to yield information about overall characteristics of brain metabolism, some means must be used to sort out the functions which might be assigned to each structure. The task is further complicated by the enormous metabolic rate of brain which brings about marked changes in the distribution and composition of metabolites and small molecules within seconds of interruption of the blood supply. Thus, all methods which require handling of wet brain tissue can be expected to produce results which can only be applied to the living brain with major reservations.