Chromatolysis in a pair of identifiable metathoracic neurons in the cockroach, Diploptera punctata

The effect of axonal transection upon a specific pair of identifiable nerve cell bodies in the metathoracic ganglion of the cockroach, Diploptera punctata, was studied by electron microscopy. The response of these cells resembles vertebrate chromatolysis in most respects and occurs in two phases : initially, the Golgi bodies decrease in size and the Nissl bodies become more concentrated next to the nucleus and less concentrated in the periphery of the perikaryon; the morphology then changes to one that is more directly concerned with active regeneration of the axon. Autoradiographic experiments showed that the initial changes in basophilia depend primarily upon movement of the Nissl bodies toward the nucleus rather than upon synthesis of new RNA.