COOLING OF PERIPHERAL MYELINATED AXONS RETARDS WALLERIAN DEGENERATION

The histological and ultrastructural status of intact and severed axon s was examined in the ventral tail nerve of rats whose tails were main tained at 32, 23, and 13 degrees C. Compared to contralateral intact n erves, distal (anucleate) portions of severed myelinated axons morphol ogically and ultrastructurally degenerated within 3 days at 32 degrees C and within 6 days at 23 degrees C. In contrast, anucleate myelinate d axons in ventral tail nerves maintained at 13 degrees C did not dege nerate for at least 10 days. These and other data suggest that rapid W allerian degeneration of anucleate myelinated axons is not an inevitab le result of axonal severance in mammals. (C) 1995 Academic Press,Inc.