Abstract
Circadian rhythms are daily adjusted to the environmental day/night cycle by photic input via the retinohypothalamic tract (RHT). Recent studies indicate that melanopsin, a newly identified opsin-like molecule, is involved in the light responsiveness of retinal ganglion cells (RGCs) constituting the RHT. In the present study, we examined the expression of melanopsin at the mRNA and protein level during a day/night cycle and during prolonged periods of light and darkness in the retina of albino Wistar rats. We observed a diurnal change in melanopsin, with mRNA level being highest at early subjective night and protein level highest at late subjective day. Prolonged exposure to darkness significantly increased melanopsin mRNA level as early as the first day, and the expression continued to increase during 5 d in darkness. The decrease in mRNA level during exposure to constant light was slower. After 48 h of light, the melanopsin mRNA level was significantly reduced, and an almost undetectable level was found after 5 d. The induction of melanopsin by darkness was even more pronounced if darkness was preceded by light suppression for 5 d. By use of immunohistochemistry, we showed that darkness increased the amount of protein in the dendritic processes, resulting in a dense network covering the entire retina. Constant light decreased melanopsin immunostaining time dependently, beginning in the distal dendrites and progressing to the proximal dendrites and the soma. Our observations suggest that the intrinsic light-responsive RGCs adapt their expression of the putative circadian photopigment melanopsin to environmental light and darkness.
Similar content being viewed by others
References
Belenky M. A., Smeraski C. A., Provencio I., Sollars P. J., and Pickard G. E. (2003) Melanopsin retinal ganglion cells receive bipolar and amacrine cell synapses. J. Comp. Neurol. 460, 380–393.
Berson D. M., Dunn F. A., and Takao M. (2002) Photo-transduction by retinal ganglion cells that set the circadian clock. Science 295, 1070–1073.
Cagampang F. R., Yang J., Nakayama Y., Fukuhara C., and Inouye S. T. (1994) Circadian variation of arginine-vasopressin messenger RNA in the rat suprachiasmatic nucleus. Brain Res. Mol. Brain Res. 24, 179–184.
Castrucci A. D. L., Ihara N., Doyle S. E., Rollag M. D., Provencio I., and Menaker M. (2004) Light regulation of melanopsin positive retinal ganglion cells in the albino hamster. Invest. Ophthalmol. Vis. Sci. 45, Abstr. 4645.
Chomczynski P. and Sacchi N. (1987) Single-step methods of RNA isolation by acid guanidium thiocyanatephenol-chloroform extraction. Anal. Biochem. 162, 156–159.
Dacey D. M., Liao H. W., Peterson B. B., Robinson F. R., Smith V. C., Pokorny J., et al. (2005) Melanopsin-expressing ganglion cells in primate retina signal colour and irradiance and project to the LGN. Nature 433, 749–754.
Fahrenkrug J., Nielsen H. S., and Hannibal J. (2004) Expression of melanopsin during development of the rat retina. Neuroreport 15, 781–784.
Field M. D., Maywood E. S., O’Brien J. A., Weaver D. R., Reppert S. M., and Hastings M. H. (2000) Analysis of clock proteins in mouse SCN demonstrates phylogenetic divergence of the circadian clockwork and resetting mechanisms. Neuron 25, 437–447.
Gooley J. J., Lu J., Fischer D., and Saper C. B. (2003) A broad role for melanopsin in nonvisual photoreception. J. Neurosci. 23, 7093–7106.
Hannibal J. (2002) Neurotransmitters of the retino-hypothalamic tract. Cell Tissue Res. 309, 73–88.
Hannibal J. and Fahrenkrug J. (2004) Melanopsin containing retinal ganglion cells are light responsive from birth. Neuroreport 15, 2317–2320.
Hannibal J., Hindersson P., Knudsen S. M., Georg B., and Fahrenkrug J. (2002) The photopigment melanopsin is exclusively present in PACAP containing retinal ganglion cells of the retinohypothalamic tract. J. Neurosci. 22(RC191), 1–7.
Hannibal J., Hindersson P., Óstergaard J., Georg B., Heegaard S., Larsen P. J., and Fahrenkrug J. (2004) Melanopsin is expressed in PACAP containing retinal ganglion cells of the human retinohypothalamic tract. Invest. Ophthalmol. Vis. Sci. 45, 4202–4209.
Hannibal J., Mikkelsen J. D., Fahrenkrug J., and Larsen P. J. (1995) Pituitary adenylate cyclase-activating peptide gene expression in corticotropin-releasing factor-containing parvicellular neurons of the rat hypothalamic paraventricular nucleus is induced by colchicines, but not by adrenalectomy, acute osmotic, ether, or restraint stress. Endocrinology 136, 4116–4124.
Hattar S., Liao H. W., Takao M., Berson D. M., and Yau K. W. (2002) Melanopsin-containing retinal ganglion cells: architecture, projections, and intrinsic photosensitivity. Science 295, 1065–1070.
Klein D. C., Moore R. Y., and Reppert S. M. (1991) Suprachiasmatic nucleus: The Mind’s Clock, Oxford University Press, New York.
Lucas R. J., Hattar S., Takao M., Berson D. M., Foster R. G., and Yau K. W. (2003) Diminished papillary light reflex at high irradiances in melanopsin-knockout mice. Science 299, 245–247.
Melyan Z., Tarttelin E. E., Bellingham J., Lucas R. J., and Hankins M. W. (2005) Addition of human melanopsin renders mammalian cells photoresponsive. Nature 433, 741–745.
Morin L. P., Blanchard J. H., and Provencio I. (2003) Retinal ganglion cells projections to the hamster suprachiasmatic nucleus, intergeniculate leaflet and visual midbrain: bifurcation and melanopsin immunoreactivity. J. Comp. Neurol. 465, 401–416.
Newman L. A., Walker M. T., Brown R. L., Cronin T. W., and Robinson P. R. (2003) Melanopsin forms a functional short-wavelength photopigment. Biochemistry 42, 12734–12738.
Panda S., Nayak S. K., Campo B., Walker J. R., Hogenesch J. B., and Jegla T. (2005) Illumination of melanopsin signaling pathway. Science 307, 600–604.
Panda S., Sato T. K., Castrucci A. M., Rollag M. D., DeGrip W. J., Hogenesch J. B., et al. (2002) Melanopsin (Opn4) requirement for normal light-induced circadian phase shifting. Science 298, 2213–2216.
Provencio I., Jiang G., De grip W. J., Hayes W. P., and Rollag M. D. (1998) Melanopsin: an opsin in melanophores, brain, and eye. Proc. Natl. Acad. Sci. U. S. A. 95, 340–345.
Provencio I., Rollag M. D., and Castrucci A. M. (2002) Photoreceptive net in the mammalian retina. This mesh of cells may explain how some blind mice can still tell day from night. Nature 415, 493.
Qiu X., Kumbalasiri T., Carlson S. M., Wong K. Y., Krishna V., Provencio I., and Berson D. M. (2005) Induction of photosensitivity by heterologous expression of melanopsin. Nature 433, 745–749.
Reppert S. M. and Weaver D. R. (2002) Coordination of circadian timing in mammals. Nature 418, 935–941.
Ruby N. F., Brennan T. J., Xie X., Cao V., Franken P., Heller H. C., and O’Hara B. F. (2002) Role of melanopsin in circadian responses to light. Science 298, 2211–2213.
Sakamoto K., Liu C., and Tosini G. (2004) Classical photoreceptors regulate melanopsin mRNA levels in the rat retina. J. Neurosci. 24, 9693–9697.
Sancar A. (2000) Cryptochrome: the second photoactive pigment in the eye and its role in circadian photoreception. Annu. Rev. Biochem. 69, 31–67.
Semo M., Peirson S., Lupi D., Lucas R. J., Jeffery G., and Foster R. G. (2003) Melanopsin retinal ganglion cells and the maintenance of circadian and papillary responses to light in aged rodles/coneless (rd/rd cl) mice. Eur. J. Neurosci. 17, 1793–1801.
Sollars P. J., Smeraski C. A., Kaufman J. D., Ogilvie M. D., Provencio I., and Pickard G. E. (2003) Melanopsin and non-melanopsin expressing retinal ganglion cells innervate the hypothalamic suprachiasmatic nucleus. Vis. Neurosci. 20, 601–610.
Van Gelder R. N., Gibler T. M., Tu D., Embry K., Selby C. P., Thompson C. L., and Sancar A. (2002) Pleiotropic effects of cryptochromes 1 and 2 on free-running and light-entrained murine circadian rhythms. J. Neurogenet. 16, 181–203.
Warren E. J., Allen C. N., Brown R. L., and Robinson D. W. (2003) Intrinsic light responses of retinal ganglion cells projecting to the circadian system. Eur. J. Neurosci. 17, 1727–1735.
Wong K. Y., Dunn F. A., and Berson D. M. (2004) Adaptation in ganglion-cell photoreceptors. Soc. Neurosci. 750, 7.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hannibal, J., Georg, B., Hindersson, P. et al. Light and darkness regulate melanopsin in the retinal ganglion cells of the albino wistar rat. J Mol Neurosci 27, 147–155 (2005). https://doi.org/10.1385/JMN:27:2:147
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1385/JMN:27:2:147