2026-03-13T01:21:50Z https://aino.repo.nii.ac.jp/oai

oai:aino.repo.nii.ac.jp:00000347 2025-09-11T06:10:05Z 7:39

Degenerative and of regenerative changes in the dorsal funiculus of the cryoinjured spinal cord of rats -electron microscopic study- Nakai, Yoshiyasu Nakai Yoshiyasu Nakano, Norihiko Nakano Norihiko Endo, Katsuaki Endo Katsuaki Noda, Toru Noda Toru Yamada, Yoshihiro Yamada Yoshihiro Suzuki, Yoshihisa Suzuki Yoshihisa Ide, Chizuka Ide Chizuka spinal cord cryoinjury regeneration electon microscopy oligodendrocyte Schwann cell myelination The morphological changes were examined in the dorsal funiculus after cryoinjury to the spinal cord at Th10 in the rat. Cryoinjury was performed by contacting a liquid nitrogen-frozen metal rod with the dorsal surface of the spinal cord. The frozen spinal cord was thawed spontaneously. This freeze-thawing treatment was repeated three times. The histological changes were examined by light and electron microscopy from 2 to 60 days after cryoinjury. The present study focused on the electron microscopic findings of the degenerative and regenerative changes of nerve fibers and glial cells following injury. In typical Waller degeneration, myelin sheaths of degenerated axons were separated from oligodendrocytes, and phagocytozed by macrophages. Within the lesion, while glial cells including oligodendrocytes were degraded, some axons were rescued from the damage, surviving as demyelinated axons after the degradation of associated oligodendrocytes. Such demyelinated axons were later remyelinated by oligodendrocytes or Schwann cells. This might be a major factor contributing to the locomotive recovery of the animal. Growth cones were formed even after a long period following cryoinjury at the proximal stump of the injured nerves. This suggests that nerve fibers have a strong ability to regenerate in the spinal cord dorsal funiculus. A cavity was usually formed in the epicenter to rostral part of the lesion. Cavity formation is a critical barrier to spinal cord regeneration. The main strategies for spinal cord regeneration might be to rescue and restore neural tissues from degeneration, and prevent cavity formation by providing a sufficient blood supply to ensure tissue survival and axonal outgrowth. 2009-03-31 eng departmental bulletin paper https://aino.repo.nii.ac.jp/records/347 1348480X AINO JOURNAL 7 1 11 33 43 https://aino.repo.nii.ac.jp/record/347/files/KJ00007502819.pdf application/pdf 1.1 MB 2019-03-27