The neuroglial response to injury following spinal cord transection in the goldfish

The spinal cord of nine goldfish was transected and studied 3 months later with conventional histological stains and by immunofluorescence with antibodies to the glial fibrillary acidic protein, a brain specific protein in fibrous astrocytes. In five fish complete transection had been followed by axonal regeneration, while in two fish the proximal and distal stumps had failed to reunite and were separated by bone, cartilage and fibrous tissue. In the remaining two goldfish the transection was incomplete. Neuroglial fibers were scanty or altogether absent in the regenerated portion of the spinal cord. Fibrous gliosis was observed in the spinal cord close to the transection, but it was extremely variable in severity in different fish and in the same fish at different levels. No fibrous gliosis was present in the descending tracts.