NMDA SENSITIVITY IS NEURITE ENHANCED

GLUTAMATE toxicity in retinal ganglion cells has been well documented both in vitro and in vitro, and may play a role in both normal neurona l development and a variety of pathological states. Glutamate receptor s are found on cell bodies and neuronal processes, both axons and dend rites. Other work has suggested that one or more of these locales may play a more pronounced role in glutamate-mediated toxicity. We now rep ort that N-methyl-D-aspartate (NMDA) is more toxic to retinal ganglion cells with neurites. Cells without neurites were relatively unaffecte d by glutamate or NMDA. Cells with longer neurites or more neurite bra nch points were more likely to sustain NMDA-mediated neurotoxicity. Th ese observations suggest that glutamate-mediated loss may be mediated through NMDA receptors found on neurites, rather than through a direct effect on the cell body.