Fibronectin immunoreactivity in neural trauma.

The presence of extracellular matrix protein fibronectin (FN) at the site of neural trauma was examined using immunohistochemical methods. At 2, 4 and 7 days following a penetrating wound through the rat cerebral cortex, FN staining was detected in the neuropil and in non-neuronal cells adjacent to the wound. FN-stained cells were GFAP-negative and were identified as brain macrophages based on cell surface staining for CR3 complement receptor. Our findings suggest a role for FN in the repair of neural trauma.