Diversity among reactive astrocytes: proximal reactive astrocytes in lacerated spinal cord preferentially react with monoclonal antibody J1-31.

An Astrocyte-specific antigen recognized by monoclonal antibody J1-31 is a more intense marker for proximal reactive astrocytes in lacerated rat spinal cord than is glial fibrillary acidic protein (GFAP). Thus, MAb J1-31 recognizes reactive astrocytes in the immediate vicinity of the lesion, whereas reactive astrocytes that are located at a distance from the lesion are not detected by immunofluorescent staining. These findings are relevant to the biochemical heterogeneity manifested respectively by reactive astrocytes located proximal and distal to a laceration-type injury of the spinal cord, and those that develop following axotomy with retrograde degeneration. Reactive astrocytes in the axotomy model are not stained with MAb J1-31, but are positive for GFAP.