Rapid degeneration of glial cells during early Wallerian degeneration in the neonatal kitten spinal cord.

Around 24 hours following neonatal lumbar dorsal root transections in kittens, the disintegration of myelinated axons in the lumbar dorsal column was accompanied by the appearance of numerous pyknotic profiles. These profiles were found to represent glial cells in various stages of degeneration. At earlier and later postlesion survival times similar profiles were rare or absent. It is suggested that acute changes in the physical and/or chemical properties of myelinated axons undergoing Wallerian degeneration during a particular developmental period is incompatible with survival of certain types of glial cells. These cells may be oligodendrocytes and/or so-called type II astrocytes.