This Article Abstract Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints, Permissions and Rights Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lockley, S. W. Articles by Arendt, J. Search for Related Content PubMed PubMed Citation Articles by Lockley, S. W. Articles by Arendt, J.

Extraocular Light Exposure Does Not Suppress Plasma Melatonin in Humans

School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, UK

Abstract

Light affects the circadian axis in at least two ways. It can cause the acute suppression of pineal melatonin synthesis, and/or a phase-shift of the circadian oscillator. As recent evidence has suggested that extraocular light exposure may cause phase-shifts of the circadian clock, we have investigated whether suppression of melatonin can be induced by the same type of light exposure. In the first study subjects’ eyes were exposed to white light (2250 lux for 30 min) via a fibre optic cable. As expected, suppression of nighttime plasma melatonin levels (61 ± 6%) was observed. In the second study, light of the same quality but higher intensity (14,000 or 67,500 lux for 180 mins) was delivered in the same manner to the popliteal region behind the subjects’ knees, whilst shielding their eyes. No suppression of plasma melatonin levels (4 ± 7%) was detected in any of the subjects. Thus, extraocular photoreception, if it exists in mammals, does not affect the suprachiasmatic nuclei-pineal pathway.

This article has been cited by other articles:

				T. V. Tkatchenko, Y. Shen, and A. V. Tkatchenko Mouse Experimental Myopia Has Features of Primate Myopia Invest. Ophthalmol. Vis. Sci., March 1, 2010; 51(3): 1297 - 1303. [Abstract] [Full Text] [PDF]

				C. Cajochen, M. Munch, S. Kobialka, K. Krauchi, R. Steiner, P. Oelhafen, S. Orgul, and A. Wirz-Justice High Sensitivity of Human Melatonin, Alertness, Thermoregulation, and Heart Rate to Short Wavelength Light J. Clin. Endocrinol. Metab., March 1, 2005; 90(3): 1311 - 1316. [Abstract] [Full Text] [PDF]

				M. Ruger, M. C. M. Gordijn, D. G. M. Beersma, B. de Vries, and S. Daan Acute and Phase-Shifting Effects of Ocular and Extraocular Light in Human Circadian Physiology J Biol Rhythms, October 1, 2003; 18(5): 409 - 419. [Abstract] [PDF]

				M. Rea, M. Figueiro, and J. Bullough Circadian photobiology: an emerging framework for lighting practice and research Lighting Research and Technology, September 1, 2002; 34(3): 177 - 187. [Abstract] [PDF]

				K. Lushington, R. Galka, L. N. Sassi, D. J. Kennaway, and D. Dawson Extraocular Light Exposure Does Not Phase Shift Saliva Melatonin Rhythms in Sleeping Subjects J Biol Rhythms, August 1, 2002; 17(4): 377 - 386. [Abstract] [PDF]

				R. G. Foster Keeping an Eye on the Time : The Cogan Lecture Invest. Ophthalmol. Vis. Sci., May 1, 2002; 43(5): 1286 - 1298. [Full Text] [PDF]

				P. J. Murphy and S. S. Campbell Enhancement of REM sleep during extraocular light exposure in humans Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2001; 280(6): R1606 - R1612. [Abstract] [Full Text] [PDF]

				E. L. Smith III, D. V. Bradley, A. Fernandes, L.-F. Hung, and R. G. Boothe Continuous Ambient Lighting and Eye Growth in Primates Invest. Ophthalmol. Vis. Sci., May 1, 2001; 42(6): 1146 - 1152. [Abstract] [Full Text]

				C. J. Saldanha, A.-J. Silverman, and R. Silver Direct Innervation of GnRH Neurons by Encephalic Photoreceptors in Birds J Biol Rhythms, February 1, 2001; 16(1): 39 - 49. [Abstract] [PDF]

				J. M Zeitzer, D.-J. Dijk, R. E Kronauer, E. N Brown, and C. A Czeisler Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression J. Physiol., August 1, 2000; 526(3): 695 - 702. [Abstract] [Full Text] [PDF]

				M. von Schantz, I. Provencio, and R. G. Foster Recent Developments in Circadian Photoreception: More Than Meets the Eye Invest. Ophthalmol. Vis. Sci., June 1, 2000; 41(7): 1605 - 1607. [Full Text]

				G. Jean-Louis, D. F. Kripke, R. J. Cole, and J. A. Elliott No Melatonin Suppression by Illumination of Popliteal Fossae or Eyelids J Biol Rhythms, June 1, 2000; 15(3): 265 - 269. [Abstract] [PDF]

This Article Abstract Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints, Permissions and Rights Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lockley, S. W. Articles by Arendt, J. Search for Related Content PubMed PubMed Citation Articles by Lockley, S. W. Articles by Arendt, J.