Increased myelination related enzymatic activities in neuron-glial heterokarya

Two enzymatic activities associated with myelination were determined in a neuron-glial heterokaryon system. Significant increases of 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNP) and UDP-galactose-ceramide galactosyl transferase (CGalt) activities were noted in heterokarya produced in vitro between 17-day-old rat cerebral neurons and differentiated cultured rat glioma (C6) cells; rat cerebral neurons and calf brain white matter glial cells or differentiated neuroblastoma 2a cells and differentiated C6 cells. Morphological expression of differentiation, such as neurite extension, was also noted in the heterokarya. Findings suggest that the glial expression of myelination related enzymatic activities could be under a neuronal regulatory control and further suggest that the interaction of neurons and glia is necessary for myelinogenesis and maintenance of the myelin sheath components.