This Article Full Text Full Text (PDF) A correction has been published Submit a related Letter to the Editor Purchase Article View Shopping Cart 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 Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Smith, K. A. Articles by Czeisler, C. A. Search for Related Content PubMed PubMed Citation Articles by Smith, K. A. Articles by Czeisler, C. A.

Adaptation of Human Pineal Melatonin Suppression by Recent Photic History

Division of Sleep Medicine, Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115

Address all correspondence and requests for reprints to: Charles A. Czeisler, Ph.D., M.D., Division of Sleep Medicine, Brigham & Women’s Hospital, Harvard Medical School, 221 Longwood Suite 438, Boston, Massachusetts 02115. E-mail: caczeisler{at}hms.harvard.edu.

The human circadian pacemaker controls the timing of the release of the pineal hormone melatonin, which promotes sleep, decreases body temperature, and diminishes cognitive performance. Abnormal melatonin secretion has been observed in psychiatric and circadian disorders. Although melatonin secretion is directly suppressed by exposure to light in a nonlinear intensity-dependent fashion, little research has focused on the effect of prior photic history on this response. We examined eight subjects in controlled laboratory conditions using a within-subjects design. Baseline melatonin secretion was monitored under constant routine conditions and compared with two additional constant routines with a fixed light stimulus for 6.5 h of 200 lux (50 µW/cm²) after approximately 3 d of photic exposure during the subjective day of either about 200 lux (50 µW/cm²) or about 0.5 lux (0.15 µW/cm²). We found a significant increase in melatonin suppression during the stimulus after a prior photic history of approximately 0.5 lux compared with approximately 200 lux, revealing that humans exhibit adaptation of circadian photoreception. Such adaptation indicates that translation of a photic stimulus into drive on the human circadian pacemaker involves more complex temporal dynamics than previously recognized. Further elucidation of these properties could prove useful in potentiating light therapies for circadian and affective disorders.

This work was supported in part by National Institutes of Mental Health Grant 5R01-MH45130 and National Aeronautics and Space Administration Cooperative Agreement NCC9-58 with the National Space and Biomedical Research Institute and was carried out in a General Clinical Research Center supported by National Institutes of Health Grant MO1-RR02635. K.S. also received support from the Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology. K.S. and M.S. are funded in part as research fellows on National Institutes of Health General Clinical Research Center Grant MO1-RR02635.

This article has been cited by other articles:

				M. Rufiange, C. Beaulieu, P. Lachapelle, and M. Dumont Circadian Light Sensitivity and Rate of Retinal Dark Adaptation in Indoor and Outdoor Workers J Biol Rhythms, October 1, 2007; 22(5): 454 - 457. [PDF]

				E. Drouyer, C. Rieux, R. A. Hut, and H. M. Cooper Responses of Suprachiasmatic Nucleus Neurons to Light and Dark Adaptation: Relative Contributions of Melanopsin and Rod Cone Inputs J. Neurosci., September 5, 2007; 27(36): 9623 - 9631. [Abstract] [Full Text] [PDF]

				J. B. Zawilska, A. Lorenc, M. Berezinska, B. Vivien-Roels, P. Pevet, and D. J. Skene Photoperiod-Dependent Changes in Melatonin Synthesis in the Turkey Pineal Gland and Retina Poult. Sci., July 1, 2007; 86(7): 1397 - 1405. [Abstract] [Full Text] [PDF]

				S. Higuchi, Y. Motohashi, K. Ishibashi, and T. Maeda Influence of eye colors of Caucasians and Asians on suppression of melatonin secretion by light Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2352 - R2356. [Abstract] [Full Text] [PDF]

				C. Gronfier, K. P. Wright Jr., R. E. Kronauer, and C. A. Czeisler Entrainment of the human circadian pacemaker to longer-than-24-h days PNAS, May 22, 2007; 104(21): 9081 - 9086. [Abstract] [Full Text] [PDF]

				S. A. Jasser, J. P. Hanifin, M. D. Rollag, and G. C. Brainard Dim light adaptation attenuates acute melatonin suppression in humans. J Biol Rhythms, October 1, 2006; 21(5): 394 - 404. [Abstract] [PDF]

				K. Ackermann, R. Bux, U. Rub, H.-W. Korf, G. Kauert, and J. H. Stehle Characterization of Human Melatonin Synthesis Using Autoptic Pineal Tissue Endocrinology, July 1, 2006; 147(7): 3235 - 3242. [Abstract] [Full Text] [PDF]

				A. Kawinska, M. Dumont, B. Selmaoui, J. Paquet, and J. Carrier Are Modifications of Melatonin Circadian Rhythm in the Middle Years of Life Related to Habitual Patterns of Light Exposure? J Biol Rhythms, October 1, 2005; 20(5): 451 - 460. [Abstract] [PDF]

				L. Yan, N. C. Foley, J. M. Bobula, L. J. Kriegsfeld, and R. Silver Two Antiphase Oscillations Occur in Each Suprachiasmatic Nucleus of Behaviorally Split Hamsters J. Neurosci., September 28, 2005; 25(39): 9017 - 9026. [Abstract] [Full Text] [PDF]

				J. M. Zeitzer, S. B. S. Khalsa, D. B. Boivin, J. F. Duffy, T. L. Shanahan, R. E. Kronauer, and C. A. Czeisler Temporal dynamics of late-night photic stimulation of the human circadian timing system Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2005; 289(3): R839 - R844. [Abstract] [Full Text] [PDF]

				G. C. Brainard and J. P. Hanifin Photons, Clocks, and Consciousness J Biol Rhythms, August 1, 2005; 20(4): 314 - 325. [Abstract] [PDF]

				J. F. Duffy and K. P. Wright Jr. Entrainment of the Human Circadian System by Light J Biol Rhythms, August 1, 2005; 20(4): 326 - 338. [Abstract] [PDF]

				R. E. Mistlberger and D. J. Skene Nonphotic Entrainment in Humans? J Biol Rhythms, August 1, 2005; 20(4): 339 - 352. [Abstract] [PDF]

				H. J. Burgess and C. I. Eastman Short Nights Attenuate Light-Induced Circadian Phase Advances in Humans J. Clin. Endocrinol. Metab., August 1, 2005; 90(8): 4437 - 4440. [Abstract] [Full Text] [PDF]

				K. P. Wright Jr, C. Gronfier, J. F. Duffy, and C. A. Czeisler Intrinsic Period and Light Intensity Determine the Phase Relationship between Melatonin and Sleep in Humans J Biol Rhythms, April 1, 2005; 20(2): 168 - 177. [Abstract] [PDF]