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 (C 6) cells; rat cerebral neurons and calf brain white matter glial cells or differentiated neuroblastoma 2a cells and differentiated C 6 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.