Astrocytes in the aged rat spinal cord fail to increase GFAP mRNA following sciatic nerve axotomy

Aging in the brain is associated with specific changes in the astrocyte population. The present study establishes that similar changes occur in the aging spinal cord. The levels of glial fibrillary acidic protein (GFAP) mRNA were significantly increased 0.4-fold in aged 8- to 17-month-old rats compared to young 2-month-old rats. The ability of astrocytes in the aging spinal cord to respond to a non-invasive CNS injury was compared to young rats 4 days following sciatic nerve axotomy. The level of GFAP mRNA was significantly increased 0.5-fold in the young rats in response to axotomy. In contrast, the level of GFAP mRNA in aged rats did not increase following injury above that present in non-axotomized rats of the same age.