UC San Diego

Glaucoma is a common cause of blindness characterized by the degeneration of optic nerve and retinal ganglion cells (RGC). A longstanding question in glaucoma research is whether certain RGC types are more susceptible to glaucoma than other RGC types. It is well understood that the mammalian retina contains a diverse population of RGCs - humans have ̃20 distinct RGC types; each cell type exhibits unique morphological and physiological properties. Given the diversity of RGC types in the retina, it is plausible that different cell types respond differently to glaucoma and thus, certain cell types may degenerate at earlier time points than others. Determining whether specific RGC types degenerate at earlier time points can have important clinical impact on early detection and treatment of glaucoma. To study whether certain RGC types degenerate at earlier time points, we used a large-scale multi-electrode system to record the action potentials of hundreds of RGCs simultaneously in healthy and optic nerve crushed rat retinas. ̃9 distinct RGC types were identified in the healthy rat retina based on unique light response and intrinsic spiking properties. The results in the healthy rat retina were compared to the optic nerve crushed rat retina to assess whether certain RGC types degenerated at earlier time points following optic nerve crush. The current results show that 2 RGC types degenerate selectively at ̃10 days after optic nerve crush