A Role for Melanopsin in Alpha Retinal Ganglion Cells and Contrast Detection

Tiffany M. Schmidt*, Nazia M. Alam, Shan Chen, Paulo Kofuji, Wei Li, Glen T. Prusky, Samer Hattar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

122 Scopus citations


Distinct subclasses of retinal ganglion cells (RGCs) mediate vision and nonimage-forming functions such as circadian photoentrainment. This distinction stems from studies that ablated melanopsin-expressingintrinsically photosensitive RGCs (ipRGCs) and showed deficits in nonimage-forming behaviors, but not image vision. However, we show that the ON alpha RGC, a conventional RGC type, is intrinsically photosensitive in mammals. In addition to their classical response to fast changes in contrast through rod/cone signaling, melanopsin expression allows ON alpha RGCs to signal prior light exposure and environmental luminance over long periods of time. Consistent with the high contrast sensitivity of ON alpha RGCs, mice lacking either melanopsin or ON alpha RGCs have behavioral deficits in contrast sensitivity. These findings indicate a surprising role for melanopsin and ipRGCs in vision.

Original languageEnglish (US)
Pages (from-to)781-788
Number of pages8
Issue number4
StatePublished - May 21 2014

ASJC Scopus subject areas

  • Neuroscience(all)


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