Summary
This thesis characterizes the intraretinal signaling of ipRGCs, showing that all six ipRGC types are electrically coupled to amacrine cells primarily via connexin36, with coupling enhanced by NMDA receptor expression. Understanding these pathways has implications for designing lighting that leverages ipRGC sensitivity in visually impaired populations and for refining melanopsin-based lighting models.
Key Findings
- All six ipRGC types are electrically coupled to amacrine cells, primarily via connexin36 (Cx36) gap junctions.
- A subset of ipRGC-coupled amacrine cells are immunopositive for bNOS, nNOS, NPY, or serotonin (5-HT), suggesting diverse downstream signaling.
- ipRGC–amacrine cell coupling is enhanced in the presence of NMDA receptor expression in ipRGCs.
- Rods, cones, and melanopsin contribute differentially to image-forming visual behavior, with distribution of coupled amacrine cells being region-specific across the retina.
Categories
The Science of Light: Detailed investigation of melanopsin-containing ipRGC signaling pathways, including gap-junction coupling via connexin36, glutamatergic inputs, and contributions to both image-forming and non-image-forming visual functions.
Author(s)
K Harrison
Publication Year
2020
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