The circadian response of intrinsically photosensitive retinal ganglion cells


Autoria(s): Zele, Andrew J.; Feigl, Beatrix; Smith, Simon S.; Markwell, Emma L.
Data(s)

14/03/2011

Resumo

Intrinsically photosensitive retinal ganglion cells (ipRGC) signal environmental light level to the central circadian clock and contribute to the pupil light reflex. It is unknown if ipRGC activity is subject to extrinsic (central) or intrinsic (retinal) network-mediated circadian modulation during light entrainment and phase shifting. Eleven younger persons (18–30 years) with no ophthalmological, medical or sleep disorders participated. The activity of the inner (ipRGC) and outer retina (cone photoreceptors) was assessed hourly using the pupil light reflex during a 24 h period of constant environmental illumination (10 lux). Exogenous circadian cues of activity, sleep, posture, caffeine, ambient temperature, caloric intake and ambient illumination were controlled. Dim-light melatonin onset (DLMO) was determined from salivary melatonin assay at hourly intervals, and participant melatonin onset values were set to 14 h to adjust clock time to circadian time. Here we demonstrate in humans that the ipRGC controlled post-illumination pupil response has a circadian rhythm independent of external light cues. This circadian variation precedes melatonin onset and the minimum ipRGC driven pupil response occurs post melatonin onset. Outer retinal photoreceptor contributions to the inner retinal ipRGC driven post-illumination pupil response also show circadian variation whereas direct outer retinal cone inputs to the pupil light reflex do not, indicating that intrinsically photosensitive (melanopsin) retinal ganglion cells mediate this circadian variation.

Formato

application/pdf

Identificador

http://eprints.qut.edu.au/40925/

Publicador

Public Library of Science

Relação

http://eprints.qut.edu.au/40925/1/Smith_PLoS_Circadian_Response.pdf

DOI:10.1371/journal.pone.0017860

Zele, Andrew J., Feigl, Beatrix, Smith, Simon S., & Markwell, Emma L. (2011) The circadian response of intrinsically photosensitive retinal ganglion cells. PLoS ONE, 6(3), pp. 1-8.

Direitos

Copyright 2011 The Authors

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Fonte

Centre for Accident Research & Road Safety - Qld (CARRS-Q); Faculty of Health; Institute of Health and Biomedical Innovation; School of Optometry & Vision Science; School of Psychology & Counselling

Palavras-Chave #111300 OPTOMETRY AND OPHTHALMOLOGY #photosensitive retinal ganglion cells #ipRGC #central circadian clock
Tipo

Journal Article