Abstract
Research over the past decade has focused increasingly on the photoreceptor mechanisms that regulate the circadian system in all forms of life. Some of the results to emerge are surprising. For example, the rods and cones within the mammalian eye are not required for the alignment (entrainment) of circadian rhythms to the dawn-dusk cycle. There exists a population of directly light-sensitive ganglion cells within the eye that act as brightness detectors; these regulate both circadian rhythms and melatonin synthesis. An understanding of these “circadian photoreceptor” pathways, and the features of the light environment used for entrainment, have been and will continue to be heavily dependent on the appropriate use and measurement of light stimuli. Furthermore, if results from different laboratories, or species, are to be compared in any meaningful sense, standardized methods for light measurement and manipulation need to be adopted by circadian biologists. To this end, we describe light measurement in terms of both radiometric and photometric units and consider the appropriate use of light as a stimulus in circadian experiments. In addition, the construction of action spectra has been very helpful in associating photopigments with particular responses in a broad range of photobiological systems. Because the identity of the photopigments mediating circadian responses to light are often not known, we have also taken this opportunity to provide a step-by-step approach to conducting action spectra, including the construction of irradiance response curves, the calculation of relative spectral sensitivities, photopigment template fitting, and the underlying assumptions behind this approach. The aims of this chapter are to provide an accessible introduction to photobiological methods and explain why these approaches need to be applied to the study of circadian systems.
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References
Roenneberg, T., and Foster, R. G. (1997) Twilight times: light and the circadian system. Photochem. Photobiol. 66, 549–561.
Ralph, M. R., Foster, R. G., Davis, F. C., and Menaker, M. (1990) Transplanted suprachiasmatic nucleus determines circadian period. Science 247, 975–978.
Moore, R., Speh, J., and Card, J. (1995) The retinohypothalamic tract originates from a distinct subset of retinal ganglion cells. J. Comp. Neurol. 352, 351–366.
Provencio, I., Cooper, H. M., and Foster, R. G. (1998) Retinal projections in mice with inherited retinal degeneration: implications for circadian photoentrainment. J. Comp. Neurol. 395, 417–439.
Foster, R. G. (1998) Shedding light on the biological clock. Neuron 20, 829–832.
Foster, R. G., Provencio, I., Hudson, D., Fiske, S., De Grip, W., and Menaker, M. (1991) Circadian photoreception in the retinally degenerate mouse (rd/rd). J Comp Physiol (A) 169, 39–50.
Lucas, R. J., Freedman, M. S., Munoz, M., Garcia-Fernandez, J. M., and Foster, R. G. (1999) Regulation of the mammalian pineal by non-rod, non-cone, ocular photoreceptors. Science 284, 505–507.
Freedman, M. S., Lucas, R. J., Soni, B., et al. (1999) Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors. Science 284, 502–504.
Lucas, R. J., Douglas, R. H., and Foster, R. G. (2001) Characterization of an ocular photopigment capable of driving pupillary constriction in mice. Nat. Neurosci. 4, 621–626.
Mrosovsky, N., Lucas, R., and Foster, R. (2001) Persistence of masking responses to light in mice lacking rods and cones. J. Biol. Rhythms 16, 585–587.
Berson, D. M., Dunn, F. A., and Takao, M. (2002) Phototransduction by retinal ganglion cells that set the circadian clock. Science 295, 1070–1073.
Sekaran, S., Foster, R. G., Lucas, R. J., and Hankins, M. W. (2003) Calcium imaging reveals a network of intrinsically light-sensitive inner-retinal neurons. Curr. Biol. 13, 1290–1298.
Hattar, S., Lucas, R. J., Mrosovsky, N., et al. (2003) Melanopsin and rod-cone photoreceptive systems account for all major accessory visual functions in mice. Nature 424, 75–81.
Thapan, K., Arendt, J., and Skene, D. J. (2001) An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. J. Physiol. 535, 261–267.
Brainard, G. C., Hanifin, J. P., Greeson, J. M., et al. (2001) Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. J. Neurosci. 21, 6405–6412.
Hankins, M. W., and Lucas, R. J. (2002) The primary visual pathway in humans is regulated according to long-term light exposure through the action of a nonclassical photopigment. Curr. Biol. 12, 191–198.
Lucas, R. J., Hattar, S., Takao, M., Berson, D. M., Foster, R. G., and Yau, K. W. (2003) Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice. Science 299, 245–247.
Panda, S., Sato, T. K., Castrucci, A. M., et al. (2002) Melanopsin (Opn4) requirement for normal light-induced circadian phase shifting. Science 298, 2213–2216.
Ruby, N. F., Brennan, T. J., Xie, X., et al. (2002) Role of melanopsin in circadian responses to light. Science, 298, 2211–2213.
Foster, R. G., Hankins, M., Lucas, R. J., et al. (2003) Non-rod, non-cone photoreception in rodents and teleost fish. Novartis Found. Symp. 253, 3–23; discussion 23–30, 52–55, 102–109.
Lythgoe, J. (1979) The Ecology of Vision. Oxford University Press, Oxford, UK.
Foster, R. G., and Hankins, M. W. (2002) Non-rod, non-cone photoreception in the vertebrates. Prog. Retin. Eye Res. 21, 507–527.
Roenneberg, T., and Deng, T-S. (1997) Photobiology of the Gonyaulax circadian system I: Different phase response curves for red and blue light. Planta 202, 494–501.
Wyszecki, G., and Stiles, W. (1982) Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd ed. Wiley-Interscience, New York.
Provencio, I., and Foster, R. G. (1995) Circadian rhythms in mice can be regulated by photoreceptors with cone-like characteristics. Brain Res. 694, 183–190.
Eldred, W. D., and Nolte, J. (1978) Pineal photoreceptors: evidence for a vertebrate visual pigment with two physiological states. Vision Res. 18, 29–32.
Solessio, E., and Engbretson, G. A. (1993) Antagonistic chromatic mechanisms in photoreceptors of the parietal eye of lizards. Nature 364, 442–445.
Knowles, A., and Dartnall, H. (1977) The Photobiology of Vision. Academic Press, New York.
Bridges, C. D. B. (1959) The visual pigments of some common laboratory animals. Nature 184, 1727–1728.
Bowmaker, J. K., and Hunt, D. M. (1999) Molecular biology of photoreceptor spectral sensitivity. In: Adaptive Mechanisms in the Ecology of Vision (Archer, S. N., Djamgoz, M. B. A., Lowe, E. R., Partridge, J. C., and Vallerga, S., eds.) Kluwer Academic Publishers, Dordrecht/Boston/London.
David-Gray, Z. K., Cooper, H. M., Janssen, J. W., Nevo, E., and Foster, R. G. (1999) Spectral tuning of a circadian photopigment in a subterranean ‘blind’ mammal (Spalax ehrenbergi). FEBS Lett. 461, 343–347.
Liebman, P. A. (1972) Microspectrophotometry of of photoreceptors. In: Handbook of Sensory Physiology (Dartnall, H. J. A., ed.) Vol. VII, Part 1. Springer, Berlin, 481–528.
Bowmaker, J. K. (1984) Microspectrophotometry of vertebrate photoreceptors. Vision Res. 24, 1641–1650.
Motulsky, H., and Christapoulos, A. (2003) Fitting models to biological data using linear and nonlinear regression. GraphPad Software, Inc. Available at: http://www.graphpad.com/articles/library.cfm.
Dartnall, H. (1953) The interpretation of spectral sensitivity curves. Br. Med. Bull. 9, 24–30.
Bridges, C. D. (1967) Spectroscopic properties of porphyropsins. Vision Res. 7, 349–369.
Partridge, J. C., and De Grip, W. J. (1991) A new template for rhodopsin (vitamin A1 based) visual pigments. Vision Res. 31, 619–630.
Govardovskii, V. I., Fyhrquist, N., Reuter, T., Kuzmin, D. G., and Donner, K. (2000) In search of the visual pigment template. Vis. Neurosci. 17, 509–528.
Foster, R. G., and Follett, B. K. (1985) The involvement of a rhodopsin-like photopigment in the photoperiodic response of the Japanese quail. J. Comp. Physiol. A, 157, 519–528.
Hartwig, H-G., and van Veen, T. (1979) Spectral characteristics of visible radiations penetrating into the brain and stimulating extra-retinal photoreceptors. J. Comp. Physiol. A 120, 277–282.
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Foster, R.G., Hankins, M.W., Peirson, S.N. (2007). Light, Photoreceptors, and Circadian Clocks. In: Rosato, E. (eds) Circadian Rhythms. Methods in Molecular Biology™, vol 362. Humana Press. https://doi.org/10.1007/978-1-59745-257-1_1
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DOI: https://doi.org/10.1007/978-1-59745-257-1_1
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