Comparison of pheochromocytes with ganglion cells and neuroblasts grown in vitro.An electron microscopic and histochemical study

Distinct patterns of growth and cellular differentiation emerged when three different, but closely related, cell types were grown in vitro. Ultrastructural studies confirmed the presence of neurites and synaptic complexes in cultures of neuroblastoma and sympathetic ganglion cells. Formation of these specialized cell structures was not observed in cultured pheochromocytes, although all three cell types possessed neurosecretory (chromaffin) granules. The latter, however, varied in their ultrastructural appearance, location, and quantity in the various cell types. The lack of specialized neural processes and the increased concentration of neurosecretory granules in the cultured pheochromocytes appear to be related to their neuroreceptor function confined to the synthesis, storage, and release of hormones.