Photoreceptive net in the mammalian retina. This mesh of cells may explain how some blind mice can still tell day from night

Nature. 2002 Jan 31;415(6871):493. doi: 10.1038/415493a.


We have discovered an expansive photoreceptive 'net' in the mouse inner retina, visualized by using an antiserum against melanopsin, a likely photopigment. This immunoreactivity is evident in a subset of retinal ganglion cells that morphologically resemble those that project to the suprachiasmatic nucleus (SCN), the site of the primary circadian pacemaker. Our results indicate that this bilayered photoreceptive net is anatomically distinct from the rod and cone photoreceptors of the outer retina, and suggest that it may mediate non-visual photoreceptive tasks such as the regulation of circadian rhythms.

MeSH terms

  • Animals
  • Circadian Rhythm / physiology
  • Mammals
  • Mice
  • Photoreceptor Cells / anatomy & histology*
  • Photoreceptor Cells / physiology
  • Rod Opsins / biosynthesis
  • Suprachiasmatic Nucleus / physiology


  • Rod Opsins
  • melanopsin