Date of this Version
Zhang D-Q, Belenky MA, Sollars PJ, Pickard GE, McMahon DG (2012) Melanopsin Mediates Retrograde Visual Signaling in the Retina. PLoS ONE 7(8): e42647. doi:10.1371/journal.pone.0042647
The canonical flow of visual signals proceeds from outer to inner retina (photoreceptors→bipolar cells→ganglion cells). However, melanopsin-expressing ganglion cells are photosensitive and functional sustained light signaling to retinal dopaminergic interneurons persists in the absence of rods and cones. Here we show that the sustained-type light response of retinal dopamine neurons requires melanopsin and that the response is mediated by AMPA-type glutamate receptors, defining a retrograde retinal visual signaling pathway that fully reverses the usual flow of light signals in retinal circuits.