HISTOLOGICAL OBSERVATIONS ON WALLERIAN DEGENERATION IN SPINAL CORD OF BABOON PAPIO PAPIO

Wallerian degeneration in the spinal cord was produced by cutting dorsal roots or excising dorsal root ganglia of 19 baboons, which were allowed to survive for from 26 hours to 428 days. Histological examination shows that the myelin sheath breaks up into ellipsoids and balls within days and that these retain the staining properties of normal myelin for many weeks. Myelin breakdown products in the form of cholesterol esters do not appear in any quantity in the degenerated tract for at least 8 weeks. Neuroglial cells react rapidly but microglial proliferation does not occur for many weeks. The findings contrast with Wallerian degeneration in peripheral nerve where the breakdown products of myelin appear early and are rapidly removed. The process of myelin degeneration in central Wallerian degeneration is different from that seen in other conditions of the central nervous system such as disseminated sclerosis, allergic encephalomyelitis or infarction. © 1969 Springer-Verlag.