Melanopsin is required for non-image-forming photic responses in blind mice

Science. 2003 Jul 25;301(5632):525-7. doi: 10.1126/science.1086179. Epub 2003 Jun 26.


Although mice lacking rod and cone photoreceptors are blind, they retain many eye-mediated responses to light, possibly through photosensitive retinal ganglion cells. These cells express melanopsin, a photopigment that confers this photosensitivity. Mice lacking melanopsin still retain nonvisual photoreception, suggesting that rods and cones could operate in this capacity. We observed that mice with both outer-retinal degeneration and a deficiency in melanopsin exhibited complete loss of photoentrainment of the circadian oscillator, pupillary light responses, photic suppression of arylalkylamine-N-acetyltransferase transcript, and acute suppression of locomotor activity by light. This indicates the importance of both nonvisual and classical visual photoreceptor systems for nonvisual photic responses in mammals.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arylamine N-Acetyltransferase / genetics
  • Arylamine N-Acetyltransferase / metabolism
  • Blindness / genetics
  • Blindness / physiopathology*
  • Circadian Rhythm
  • Light Signal Transduction*
  • Light*
  • Mice
  • Mice, Inbred C3H
  • Motor Activity
  • Photoreceptor Cells, Vertebrate / physiology*
  • Reflex, Pupillary
  • Retinal Degeneration / genetics
  • Retinal Degeneration / physiopathology
  • Retinal Ganglion Cells / physiology
  • Rod Opsins / deficiency
  • Rod Opsins / genetics
  • Rod Opsins / physiology*
  • Signal Transduction
  • Suprachiasmatic Nucleus / physiology


  • Rod Opsins
  • melanopsin
  • Arylamine N-Acetyltransferase