Photoreceptor cell

This article is about cellular photoreceptors. For other types of photoreceptors, see Photoreceptor (disambiguation).
Photoreceptor cell
Functional parts of the rods and cones, which are two of the three types of photosensitive cells in the retina
Identifiers
MeSHD010786
NeuroLex IDsao226523927
FMA85613 86740, 85613
Anatomical terms of neuroanatomy

A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential.

There are currently three known types of photoreceptor cells in mammalian eyes: rods, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form an image of the environment, sight. Rods primarily mediate scotopic vision (dim conditions) whereas cones primarily mediate photopic vision (bright conditions), but the processes in each that supports phototransduction is similar.[1] The intrinsically photosensitive retinal ganglion cells were discovered during the 1990s.[2] These cells are thought not to contribute to sight directly, but have a role in the entrainment of the circadian rhythm and the pupillary reflex.

  1. ^ "eye, human." Encyclopædia Britannica. Encyclopædia Britannica Ultimate Reference Suite. Chicago: Encyclopædia Britannica, 2010.
  2. ^ Foster, R.G.; Provencio, I.; Hudson, D.; Fiske, S.; Grip, W.; Menaker, M. (1991). "Circadian photoreception in the retinally degenerate mouse (rd/rd)". Journal of Comparative Physiology A. 169 (1): 39–50. doi:10.1007/BF00198171. PMID 1941717. S2CID 1124159.