EVIDENCE FOR A REGIONAL DISTRIBUTION OF HYALURONIC-ACID IN THE RAT-BRAIN USING A HIGHLY SPECIFIC HYALURONIC-ACID RECOGNIZING PROTEIN

By means of a highly specific hyaluronic acid-recognizing protein the localization and regional distribution of hyaluronic acid was demonstr ated in the tel- and diencephalon and in the midbrain of the adult rat nervous system. Histochemistry revealed labeling associated with the plasma membrane in highly discrete nerve cell bodies of the frontopari etal cortex, the red nucleus, the zona reticulata of the substantia ni gra, the oculomotor nucleus and the reticular thalamic nucleus. A stro ng labeling without association with perikarya was demonstrated in the subgranular zone of the dentate gyrus of the hippocampal formation. T he present results open up the possibility that the hyaluronic acid fo und in high concentrations associated with some perikarya may have a s pecial role in plasticity responses in these discrete nerve cell popul ations.