AXOTOMY-INDUCED RETINAL GANGLION-CELL DEATH IN DEVELOPMENT - ITS TIMECOURSE AND ITS DIMINUTION BY ANTIOXIDANTS

Developing neurons die when deprived of trophic support from their axo nal target. Although this is generally attributed to the programmed ex pression of suicide proteins, recent data suggest that a less orderly mechanism involving oxidative stress may also be involved. We have stu died retinal ganglion cell death in the chick embryo after a contralat eral tectal lesion. The kinetics of cell death, as judged from counts of pyknotic cells, are described. In addition, we show that the pyknot ic counts are reduced following intraocular injections of the protein synthesis inhibitor cycloheximide or the antioxidants N-t-butyl-alpha- phenylnitrone and N-acetyl cysteine. Our results suggest that target d eprivation-induced ganglion cell death involves oxidative stress.