AN INTRALAMINAR ANALYSIS OF BETA-GLUCURONIDASE IN CEREBRAL CORTEX OF RAT

Abstract— Activities of β‐glucuronidase were measured microchemically in the rat within cortical layers and subcortical white matter of somatosensory and visual cortex and the dorsal hippocampus. Distributions were related to histological composition, densities of myelinated fibers, and lysosome content as indicated by acid phosphatase staining. Three zones of relatively high activities were noted. The first corresponded to the pia‐arachnoid and has been related to lysosmal particles within pericytes and macrophages of the meninges and in the pial cells. A second peak appeared in layer V and correlated well with the presence of neuronal lysosomes as detected by histochemical reaction. A third contribution was related to the presence of myelinated fibre bundles and white matter. Data from the literature and from unpublished results were cited to support the conclusion that nonlysosomal sources of enzyme in white matter included a major component from particles sedimenting with the microsomal fraction and a small component from myelin. Copyright © 1969, Wiley Blackwell. All rights reserved