ALTERED IMMUNOREACTIVITY FOR GLIAL FIBRILLARY ACIDIC PROTEIN IN ASTROCYTES WITHIN 1 H AFTER CERVICAL SPINAL-CORD INJURY

One hour after a C2 spinal cord hemisection, there are changes in astr ocyte morphology and increased glial fibrillary acidic protein immunor eactivity (GFAP IR) near the site of the lesion, Astrocytes adjacent t o the lesion display thick, richly branched processes within 1/2 segme nt rostral and caudal to the level of hemisection,Astrocytes are also enlarged and immunoreactive in gray matter regions of the spinal cord as far caudal as C4 and rostrally to C1. Sham-operated controls, under going a laminectomy and durotomy at C2, but not spinal cord hemisectio n, also exhibit a strong astroglial reaction within 1 h from C1 to C4, However, controls undergoing only a C2 laminectomy do not demonstrate alterations in GFAP IR compared to nonoperated controls, The results of this investigation suggest that spinal cord astrocytes are extremel y sensitive to both major as well as minor alterations of their microe nvironment. Rapid changes in astroglial morphology, as detected by alt ered GFAP LR, may play a role in changes in neuronal function followin g spinal cord injury. (C) 1997 Academic Press.