Peripheral nerve implant effects on survival of retinal ganglion layer cells after axotomy initiated by a penetrating lesion.
A lesion paradigm involving a small penetrating incision made through the sclera, choroid and retina of the adult rat eye creates a unique environment for the study of the damaged retina. More specifically, the dependable formation of a small focal retinal lesion makes this an ideal model for the determination of conditions that may stimulate retinal regeneration, wound repair and/or cell survival. Our previous studies have indicated that the placement of a desheathed peripheral nerve implant (PNI) into the lesioned adult rat eye: (1) initiated the rescue of retinal tissue that would normally die due to trauma; and (2) maintained the thickness and organization of most retinal layers adjacent to the lesion site, particularly the retinal ganglion cell layer (RGL). We report in the present work that a more detailed analysis of the RGL revealed a significant increase in the survival of axotomized neurons within this layer in the presence of a PNI over an 8-week post-implantation period. More specifically, there was a 60% loss of control RGL cells axotomized by the lesion 3 weeks previously in contrast to only a 30% loss in those tissues exposed to a PNI. Additional RGL cell size distribution studies point to the fact that the PNI appeared to affect the increased survival of cells greater than or equal to 70 micron2. Also the PNI effect demonstrated a specificity of response when tested against the influence of a tendon or suture implant.(ABSTRACT TRUNCATED AT 250 WORDS)
Turner
J E
JE
Department of Anatomy, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27103.
Blair
J R
JR
Chappel
E T
ET
D000818:Animals; D002452:Cell Count; D002467:Cell Nucleus / Q000502:physiology; D002470:Cell Survival; D006133:Growth Substances / Q000502:physiology; D008297:Male; D009416:Nerve Regeneration; D013508:Ophthalmologic Surgical Procedures; D010525:Peripheral Nerves / Q000378:metabolism / Q000502:physiology / Q000637:transplantation*; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology* / Q000648:ultrastructure; D012584:Sciatic Nerve / Q000637:transplantation; D013997:Time Factors
D006133:Growth Substances