CENTRAL CHROMATOLYSIS AND AXON REACTION - REAPPRAISAL

Central chromatolysis (i.e., perinuclear disruption of the Nissl substance) is apparently only one of many cellular events in the axon reaction, and the degree of chromatolysis (and other events) may vary from extensive to almost none, regardless of the outcome of the reaction. The degree of disruption of the different components of the GER [granular endoplasmic reticulum] may vary in chromatolytic cells that look very similar in the light microscope. Generally, the extent of the chromatolysis appears to be a measure of the initial cell injury but its significance in terms of cell function is not known. Regardless of the initial cellular events, the actual regeneration of the axon seems to be accompanied by a net increase in the cell body of RNA and protein synthesis. Apart from this, little is known about the functional effect of the morphological changes in the perikarya. Apparently, no massive exchange of organelles is necessary for the regenerative process.