Fine structure of chromatolytic feline motoneurons

1. (1) Electron microscopic and electron histochemical observations on chromatolytic spinal motoneurons of the cat have demonstrated the occurrence of peripherad displacement (retispersion) of the Golgi apparatus of the reacting nerve cells. Though described originally by light microscopists, retispersion has not been reported in previous ultrastructural studies of axon reaction. It is suggested that species differences and variations in the nature of the neuronal populations studied after axotomy may have bearing on the discrepancies in the literature between light microscopic and fine structural observations. 2. (2) In addition to the change in distribution of Golgi elements, chromatolytic motoneurons show an alteration in a smooth membranous system resembling the subsurface cisterns of Rosenbluth (1962). A proliferation of these elements is found in chromatolytic cells 28–60 days after axon section. It is suggested that subsurface cisterns may have a functional relationship to the cytoplasmic syntheses accompanying axonal regrowth.