Article

Non-Visual Photoreception: Sensing Light without Sight

Department of Ophthalmology, University of Washington Medical School, Seattle, Washington, USA.
Current Biology (Impact Factor: 9.57). 02/2008; 18(1):R38-9. DOI: 10.1016/j.cub.2007.11.027
Source: PubMed

ABSTRACT

Recent work in blind human subjects has confirmed the presence of a non-visual ocular photoreceptive mechanism similar to that described in blind mice. This system appears to subserve circadian photic entrainment, the pupillary light response, and a number of other aspects of neurophysiology and behavior.

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Available from: Russell Van Gelder, Nov 26, 2014
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    • "For non-visual luminance monitoring, there is thus no need for cilia or microvilli. Indeed, non-visual photoreceptors often lack these conspicuous structures altogether (Gooley et al. 2003; Gotow & Nishi 2007, 2008; Van Gelder 2008). Modelling also demonstrates that phototaxis, which requires directionality with wide angular sensitivities and intermediate integration times, can function without membrane stacking, but only during the day, and in rather shallow water (figure 4; see table S1, electronic supplementary material). "
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    • "Though they are located within the retina, these cells do not function in image formation; instead, they appear to serve a circadian function. It is for this reason that some blind people lacking rods and cones can nonetheless respond to day–night cycles (Van Gelder 2007; Zaidi et al. 2007). The cases of Platynereis, Tripedalia, and humans suggest that most animals will turn out to exhibit both types of photoreceptor cells, or at least that they had both at some stage in their ancestry (Plachetzki et al. 2005). "
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    Preview · Article · Oct 2008 · Evolution Education and Outreach
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