Format

Send to

Choose Destination
See comment in PubMed Commons below
Curr Biol. 2005 Jun 21;15(12):1099-107.

Melanopsin-dependent photoreception provides earliest light detection in the mammalian retina.

Author information

  • 1Department of Visual Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Charing Cross Hospital Campus, London, W6 8RF, United Kingdom. s.sekaran@imperial.ac.uk

Abstract

BACKGROUND:

The visual system is now known to be composed of image-forming and non-image-forming pathways. Photoreception for the image-forming pathway begins at the rods and cones, whereas that for the non-image-forming pathway also involves intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin. In the mouse retina, the rod and cone photoreceptors become light responsive from postnatal day 10 (P10); however, the development of photosensitivity of the ipRGCs remains largely unexplored.

RESULTS:

Here, we provide direct physiological evidence that the ipRGCs are light responsive from birth (P0) and that this photosensitivity requires melanopsin expression. Interestingly, the number of ipRGCs at P0 is over five times that in the adult retina, reflecting an initial overproduction of melanopsin-expressing cells during development. Even at P0, the ipRGCs form functional connections with the suprachiasmatic nucleus, as assessed by light-induced Fos expression.

CONCLUSIONS:

The findings suggest that the non-image-forming pathway is functional long before the mainstream image-forming pathway during development.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk