Alterations in glial fibrillary acidic protein immunoreactivity in the upper dorsal horn of the rat spinal cord in the course of transganglionic degenerative atrophy and regenerative proliferation.

Transection of a peripheral nerve induces marked increase in the glial fibrillary acidic protein (GFAP) immunoreactivity in the ipsilateral, segmentally related upper dorsal horn. Increase of GFAP immunoreaction is similar to, but not identical with, that observed after dorsal rhizotomy. If the peripheral nerve succeeds in regenerating, GFAP immunoreactivity in the upper dorsal horn returns to normal. It is concluded that the amount and distribution of GFAP is determined by transganglionic degenerative atrophy. Wallerian degeneration and regenerative proliferation of dorsal root axon terminals, respectively.