Alterations in temporal/spatial distribution of GFAP- and vimentin-positive astrocytes after spinal cord contusion with the New York University spinal cord injury device

Astrocytes become reactive as a result of various types of lesions and upre gulate 2 intermediate filaments, glial fibrillary acidic protein (GFAP), an d the developmentally regulated protein vimentin, Young female Sprague-Dawl ey rats were subjected to a spinal cord contusion at segment T10 using the New York University injury device. Animals were killed at 1, 2, 7, 14, and 30 days postinjury, Horizontal spinal cord sections spanning segments T7-T1 3 were assessed with antibodies to both intermediate filament proteins. The number of gray matter GFAP-positive astrocytes increased by 2 days postinj ury, with segments adjacent (proximal) to the injury site showing greater r esponses than areas several segments away (distal), By 30 days following in jury, astroglial cell numbers returned to normal levels. Vimentin-positive astrocytes also showed a graded proximal/distal response by 2 days followin g injury, Proximal regions remained significantly higher at 30 days followi ng injury than control animals, Rostral/caudal changes were also evident, w ith regions caudal to the injury showing significantly higher numbers of vi mentin positive astrocytes than those rostral, indicating that gray matter areas caudal to spinal cord injury may undergo more stress following spinal cord injury.