Regenerative sprouting of retinal ganglion cells of adult hamsters inducedby the epineurium of a peripheral nerve

Although it is known that transplantation of a peripheral nerve (PN) to the damaged central nervous system (CNS) promotes axonal regeneration, the int eractions of cellular components of the PN with CNS neurons are still not w ell defined. Schwann cells in the PN are thought to be the major element in volved in supporting CNS regeneration, but very Little information exists w ith regard to whether other PN components also play an active role. Using o ur previously established model of transplanting a PN segment into the Vitr eous to stimulate regenerative sprouting of retinal ganglion cells (RGCs), we found that the epineurium isolated from a PN which had been pre-injured by transection was able to induce RGC sprouting when implanted intravitreal ly. Since the epineurium is composed mainly of connective tissue components and is devoid of Schwann cells, our results suggest that other cellular el ements of the PN besides Schwann cells may have the potential to support CN S regeneration. (C) 1999 Elsevier Science B.V. All rights reserved.