This Article Full Text (PDF) References Alert me when this article is cited 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 Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Illnerová, H. Articles by Sumová, A. Search for Related Content PubMed PubMed Citation Articles by Illnerová, H. Articles by Sumová, A. Social Bookmarking                         What's this?

Photic Entrainment of the Mammalian Rhythm in Melatonin Production

Institute of Physiology, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic

Alena Sumová

Institute of Physiology, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic

This review summarizes studies on the photic entrainment of the circadian rhythm in the rat pineal melatonin production, namely of the rhythm in N-acetyltransferase (NAT) activity, and compares the NAT rhythm resetting with preliminary results on the resetting of an intrinsic rhythmicity in the suprachiasmatic nucleus (SCN) of the hypothalamus, namely with the entrainment of the rhythm in the light-induced c-fos gene expression. Phase delaying of the NAT rhythm after various light stimuli proceeds within 1 day with almost no transients, whereas during phase advancing of the rhythm only the morning NAT decline is phase advanced within 1 day and the evening rise phase shifts through transients. A light stimulus encompassing the middle of the night may phase delay the evening NAT rise, phase advance the morning decline, compress the rhythm waveform, and eventually lower its amplitude. Similarly, a long photoperiod compresses the NAT rhythm waveform. The magnitude of phase shifts of the NAT rhythm, as well as their direction, depends on a previous photoperiod. Phase shifts of the evening rise in c-fos gene photoinduction in the SCN and of the morning decline are similar to those of the pineal NAT rhythm after all light stimuli studied so far. The data indicate that the resetting of the rhythm in melatonin production in the rat pineal gland reflects changes in the SCN functional state and suggest that the underlying SCN pacemaking system is complex.

Key Words: circadian rhythm • entrainment • light • pineal • melatonin • N-acetyltransferase • suprachiasmatic nucleus • c-fos

Journal of Biological Rhythms, Vol. 12, No. 6, 547-555 (1997)
DOI: 10.1177/074873049701200609


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. Nikkhah, C. J. Furedi, A. D. Kennedy, G. H. Crow, and J. C. Plaizier Effects of Feed Delivery Time on Feed Intake, Milk Production, and Blood Metabolites of Dairy Cows J Dairy Sci, November 1, 2008; 91(11): 4249 - 4260. [Abstract] [Full Text] [PDF]

				S. B. S Khalsa, M. E Jewett, C. Cajochen, and C. A Czeisler A phase response curve to single bright light pulses in human subjects J. Physiol., June 15, 2003; 549(3): 945 - 952. [Abstract] [Full Text] [PDF]

				J. H. Meijer and W. J. Schwartz In Search of the Pathways for Light-Induced Pacemaker Resetting in the Suprachiasmatic Nucleus J Biol Rhythms, June 1, 2003; 18(3): 235 - 249. [Abstract] [PDF]

				J. H. Stehle, C. von Gall, C. Schomerus, and H.-W. Korf Of Rodents and Ungulates and Melatonin: Creating a Uniform Code for Darkness by Different Signaling Mechanisms J Biol Rhythms, August 1, 2001; 16(4): 312 - 325. [Abstract] [PDF]

				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]

				T. L. Shanahan, R. E. Kronauer, J. F. Duffy, G. H. Williams, and C. A. Czeisler Melatonin Rhythm Observed throughout a Three-Cycle Bright-Light Stimulus Designed to Reset the Human Circadian Pacemaker J Biol Rhythms, June 1, 1999; 14(3): 237 - 253. [Abstract] [PDF]

				C. Ribelayga, M.-L. Garidou, A. Malan, F. Gauer, C. Calgari, P. Pevet, and V. Simonneaux Photoperiodic Control of the Rat Pineal Arylalkylamine-N-Acetyltransferase and Hydroxyindole-O-Methyltransferase Gene Expression and Its Effect on Melatonin Synthesis J Biol Rhythms, April 1, 1999; 14(2): 105 - 115. [Abstract] [PDF]