Physiologic diversity and development of intrinsically photosensitive retinal ganglion cells

Neuron. 2005 Dec 22;48(6):987-99. doi: 10.1016/j.neuron.2005.09.031.


Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate numerous nonvisual phenomena, including entrainment of the circadian clock to light-dark cycles, pupillary light responsiveness, and light-regulated hormone release. We have applied multielectrode array recording to characterize murine ipRGCs. We find that all ipRGC photosensitivity is melanopsin dependent. At least three populations of ipRGCs are present in the postnatal day 8 (P8) murine retina: slow onset, sensitive, fast off (type I); slow onset, insensitive, slow off (type II); and rapid onset, sensitive, very slow off (type III). Recordings from adult rd/rd retinas reveal cells comparable to postnatal types II and III. Recordings from early postnatal retinas demonstrate intrinsic light responses from P0. Early light responses are transient and insensitive but by P6 show increased photosensitivity and persistence. These results demonstrate that ipRGCs are the first light-sensitive cells in the retina and suggest previously unappreciated diversity in this cell population.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology*
  • Action Potentials / radiation effects
  • Aging / physiology
  • Animals
  • Animals, Newborn
  • Cell Differentiation / physiology*
  • Cell Differentiation / radiation effects
  • Electrophysiology / instrumentation
  • Electrophysiology / methods
  • Light
  • Light Signal Transduction / physiology*
  • Light Signal Transduction / radiation effects
  • Membrane Potentials / physiology
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nerve Net / growth & development
  • Nerve Net / metabolism
  • Nerve Net / radiation effects
  • Organ Culture Techniques
  • Photic Stimulation
  • Reaction Time / physiology
  • Retina / growth & development*
  • Retina / metabolism
  • Retina / radiation effects
  • Retinal Ganglion Cells / classification
  • Retinal Ganglion Cells / physiology*
  • Retinal Ganglion Cells / radiation effects
  • Rod Opsins / genetics
  • Rod Opsins / metabolism*


  • Rod Opsins
  • melanopsin