APOPTOTIC GLIAL-CELL DEATH AND KINETICS IN THE SPINAL-CORD OF THE MYELIN-DEFICIENT RAT

This study examined the glial cell kinetics and death in the thoracic spinal cord of normal and myelin-deficient (rnd) rats between 1 and 21 days of age and determined whether the observed glial cell death prim arily affected oligodendrocytes and had the morphologic and molecular features of apoptosis. In the md rat spinal cord there was an increase in cell division and death in a pattern that correlated with the onse t of myelination. The dying cells were identified as oligodendrocytes ultrastructurally as many had the characteristic distention of the rou gh endoplasmic reticulum seen in the ind rat glia. Double labeling usi ng PLP in situ hybridization and a modified TUNEL method also suggeste d that the dying cells, in both mutant rats and control littermates, w ere oligodendrocytes. These findings were compared with previous studi es on the md rat optic nerve and those in other PLP mutants. (C) 1998 Wiley-Liss, Inc.