Publikationsdatum:
2009-01-02
Beschreibung:
A subset of retinal ganglion cells has recently been discovered to be intrinsically photosensitive, with melanopsin as the pigment. These cells project primarily to brain centres for non-image-forming visual functions such as the pupillary light reflex and circadian photoentrainment. How well they signal intrinsic light absorption to drive behaviour remains unclear. Here we report fundamental parameters governing their intrinsic light responses and associated spike generation. The membrane density of melanopsin is 10(4)-fold lower than that of rod and cone pigments, resulting in a very low photon catch and a phototransducing role only in relatively bright light. Nonetheless, each captured photon elicits a large and extraordinarily prolonged response, with a unique shape among known photoreceptors. Notably, like rods, these cells are capable of signalling single-photon absorption. A flash causing a few hundred isomerized melanopsin molecules in a retina is sufficient for reaching threshold for the pupillary light reflex.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2794210/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2794210/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Do, Michael Tri H -- Kang, Shin H -- Xue, Tian -- Zhong, Haining -- Liao, Hsi-Wen -- Bergles, Dwight E -- Yau, King-Wai -- F32 EY016959/EY/NEI NIH HHS/ -- F32 EY016959-01/EY/NEI NIH HHS/ -- F32 EY016959-02/EY/NEI NIH HHS/ -- F32 EY016959-03/EY/NEI NIH HHS/ -- R01 DC006904/DC/NIDCD NIH HHS/ -- R01 DC006904-01/DC/NIDCD NIH HHS/ -- R01 DC006904-02/DC/NIDCD NIH HHS/ -- R01 DC006904-03/DC/NIDCD NIH HHS/ -- R01 DC006904-04/DC/NIDCD NIH HHS/ -- R01 DC006904-05/DC/NIDCD NIH HHS/ -- R01 EY006837/EY/NEI NIH HHS/ -- R01 EY006837-16A1/EY/NEI NIH HHS/ -- R01 EY006837-18/EY/NEI NIH HHS/ -- R01 EY006837-20A1/EY/NEI NIH HHS/ -- R01 EY006837-21/EY/NEI NIH HHS/ -- R01 EY006837-22/EY/NEI NIH HHS/ -- R01 EY014596/EY/NEI NIH HHS/ -- R01 EY014596-01/EY/NEI NIH HHS/ -- R01 EY014596-02/EY/NEI NIH HHS/ -- R01 EY014596-03/EY/NEI NIH HHS/ -- R01 EY014596-04/EY/NEI NIH HHS/ -- R01 EY014596-05/EY/NEI NIH HHS/ -- R01 EY014596-06/EY/NEI NIH HHS/ -- R01 EY014596-07/EY/NEI NIH HHS/ -- R01 EY014596-07S1/EY/NEI NIH HHS/ -- R01 NS051509/NS/NINDS NIH HHS/ -- R01 NS051509-01A1/NS/NINDS NIH HHS/ -- R01 NS051509-02/NS/NINDS NIH HHS/ -- R01 NS051509-03/NS/NINDS NIH HHS/ -- R01 NS051509-04/NS/NINDS NIH HHS/ -- England -- Nature. 2009 Jan 15;457(7227):281-7. doi: 10.1038/nature07682. Epub 2008 Dec 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. mdo@jhmi.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19118382" target="_blank"〉PubMed〈/a〉
Schlagwort(e):
Action Potentials/radiation effects
;
Animals
;
Brain/metabolism
;
Kinetics
;
Mice
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
*Photons
;
Pupil/physiology/radiation effects
;
Reflex, Pupillary/radiation effects
;
Retinal Ganglion Cells/*metabolism/*radiation effects
;
Rod Opsins/*metabolism
Print ISSN:
0028-0836
Digitale ISSN:
1476-4687
Thema:
Biologie
,
Chemie und Pharmazie
,
Medizin
,
Allgemeine Naturwissenschaft
,
Physik
