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 Web of Science 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 Web of Science (4) Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Tavakoli-Nezhad, M. Articles by Schwartz, W. J. Search for Related Content PubMed PubMed Citation Articles by Tavakoli-Nezhad, M. Articles by Schwartz, W. J. Social Bookmarking                         What's this?

c-Fos Expression in the Brains of Behaviorally "Split" Hamsters in Constant Light: Calling Attention to a Dorsolateral Region of the Suprachiasmatic Nucleus and the Medial Division of the Lateral Habenula

Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts

William J. Schwartz

Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts, william.schwartz{at}umassmed.edu

"Splitting" of circadian activity rhythms in Syrian hamsters maintained in constant light appears to be the consequence of a reorganized SCN, with left and right halves oscillating in antiphase; in split hamsters, high mRNA levels characteristic of day and night are simultaneously expressed on opposite sides of the paired SCN. To visualize the splitting phenomenon at a cellular level, immunohistochemical c-Fos protein expression in the SCN and brains of split hamsters was analyzed. One side of the split SCN exhibited relatively high c-Fos levels, in a pattern resembling that seen in normal, unsplit hamsters during subjective day in constant darkness; the opposite side was labeled only within a central-dorsolateral area of the caudal SCN, in a region that likely coincides with a photo-responsive, glutamate receptor antagonist-insensitive, pERK-expressing cluster of cells previously identified by other laboratories. Outside the SCN, visual inspection revealed an obvious left-right asymmetry of c-Fos expression in the medial preoptic nucleus and subparaventricular zone of split hamsters killed during the inactive phase and in the medial division of the lateral habenula during the active phase (when the hamsters were running in their wheels). Roles for the dorsolateral SCN and the mediolateral habenula in circadian timekeeping are not yet understood.

Key Words: c-Fos • calbindin • circadian • PER • splitting • suprachiasmatic nucleus

Journal of Biological Rhythms, Vol. 20, No. 5, 419-429 (2005)
DOI: 10.1177/0748730405278443


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

This article has been cited by other articles:

				E. M. Gibson, S. A. Humber, S. Jain, W. P. Williams III, S. Zhao, G. E. Bentley, K. Tsutsui, and L. J. Kriegsfeld Alterations in RFamide-Related Peptide Expression Are Coordinated with the Preovulatory Luteinizing Hormone Surge Endocrinology, October 1, 2008; 149(10): 4958 - 4969. [Abstract] [Full Text] [PDF]

				P. Indic, W. J Schwartz, and D. Paydarfar Design principles for phase-splitting behaviour of coupled cellular oscillators: clues from hamsters with 'split' circadian rhythms J R Soc Interface, August 6, 2008; 5(25): 873 - 883. [Abstract] [Full Text] [PDF]

				L. Yan, I. Karatsoreos, J. LeSauter, D. K. Welsh, S. Kay, D. Foley, and R. Silver Exploring Spatiotemporal Organization of SCN Circuits Cold Spring Harb Symp Quant Biol, January 1, 2007; 72(0): 527 - 541. [Abstract] [PDF]