Glycogen accumulation in spinal cord motor neurons due to partial ischemia

Partial ischemia of the spinal cord in adult cats was induced by abdominal aortic ligation. The most striking abnormality was an accumulation of glycogen in large motor neurons and astroglia in the peripheral anterior horns. Little or no histological and ultrastructural abnormalities were present in these regions. The first glycogen deposits appeared after 1/2 h in glial cells, whereas glycogen accumulation in neurons was first noticeable 1 h after ligation reaching a maximum in 24 h. A gradual decrease occurred with disappearance of glycogen at 10 days. Increase in UDPG-transferase was found preceeding glycogen appearance, and increase in glycogen-phosphorylase activity occurred later concurrent with glycogen accumulation. This unique neuronal glycogen deposition may be due to the UDPG-transferase normally present in γ-motor neurons of the anterior horns. Other possible mechanisms are also considered.