Editing Signal transduction (section)

===Light===
{{Main|Visual phototransduction}}
In mammals, [[light]] controls the sense of [[Visual perception|sight]] and the [[circadian clock]] by activating light-sensitive proteins in [[photoreceptor cell]]s in the [[eye]]'s [[retina]]. In the case of vision, light is detected by [[rhodopsin]] in [[rod cells|rod]] and [[cone cells]].<ref name="burns">{{Cite journal |vauthors=Burns ME, Arshavsky VY |date=November 2005 |title=Beyond counting photons: trials and trends in vertebrate visual transduction |journal=Neuron |volume=48 |issue=3 |pages=387–401 |doi=10.1016/j.neuron.2005.10.014 |pmid=16269358 |doi-access=free}}</ref> In the case of the circadian clock, a different [[photopigment]], [[melanopsin]], is responsible for detecting light in [[intrinsically photosensitive retinal ganglion cells]].<ref>{{Cite journal |vauthors=Berson DM |date=August 2007 |title=Phototransduction in ganglion-cell photoreceptors |journal=Pflügers Archiv |volume=454 |issue=5 |pages=849–55 |doi=10.1007/s00424-007-0242-2 |pmid=17351786 |doi-access=free}}</ref>