Skip to main page content
U.S. flag

An official website of the United States government

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2011 Sep;59(9):1341-50.
doi: 10.1002/glia.21097. Epub 2010 Dec 1.

Glial cell modulation of circadian rhythms

F Rob Jackson  1
Affiliations
Review

Glial cell modulation of circadian rhythms

F Rob Jackson. Glia. 2011 Sep.

Abstract

Studies of Drosophila and mammals have documented circadian changes in the morphology and biochemistry of glial cells. In addition, it is known that astrocytes of flies and mammals contain evolutionarily conserved circadian molecular oscillators that are similar to neuronal oscillators. In several sections of this review, I summarize the morphological and biochemical rhythms of glia that may contribute to circadian control. I also discuss the evidence suggesting that glia-neuron interactions may be critical for circadian timing in both flies and mammals. Throughout the review, I attempt to compare and contrast findings from these invertebrate and vertebrate models so as to provide a synthesis of current knowledge and indicate potential research avenues that may be useful for better understanding the roles of glial cells in the circadian system.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Molecular clock and temporal expression of clock products. A: Schematic diagram of transcriptional interactions amount clock components. activation; repression. CWO may also mediate repression of output genes (not shown). B: Diurnal expression profiles for clock RNAs and proteins. Black lines represent RNA abundance profiles for per, tim and Clk. Colored lines indicate protein abundance profiles for clock proteins and immunofluorescence signals for Pigment Dispersing Factor (PDF), a clock output peptide. pCLK represents phosphorylated, activated CLK which has a circadian phase hours later than the Clk transcription rhythm. The PDF curve illustrates peptide immunoreactivity in the s-LNv dorsal projections; reduced amounts during the day are presumed to reflect release of the peptide.
Fig. 2
Fig. 2
Locations of circadian clock cells in (A) the rat suprachiasmatic nuclei (SCN) and (B) the Drosophila brain. Only one “hemisphere” of the fly brain is pictured in this image, but clock cells are bilaterally localized in the brain. The white ovals encompass clock neurons of the fly brain; PER-expressing glial cells are distributed throughout the brain. The black oval in A delineates the clock neurons and astrocyctes of the rat brain. The image of the SCN was a gift from Dr. J. Levine (U. Toronto). OC, optic chiasm; LNv, ventral lateral clock neurons; LNd, dorsal lateral clock neurons; DN1, 2 and 3, the three groups of dorsal clock neurons.
Fig. 3
Fig. 3
Ebony-containing glial cells of the fly’s optic lobe (OL) and central brain. Ebony is predominantly cytoplasmic but is not well detected in most astrocytic processes. Thus, the typical fly astrocytic cell architecture cannot be seen in this image. All Ebony-containing cells of the fly brain are glia, as indicated by a glial marker protein(not shown in this image). Note that the optic lamina, which also contains Ebony-expressing glia, is not included in this particular specimen.
Fig. 4
Fig. 4
Cellular localization dEAAT1 in the fly brain as reflected by a dEAAT1-Gal4 driver regulating expression of a UAS-CD8-GFP transgene. The CD8 moiety directs GFP to membranes of glial cell bodies and processes in the synaptic neuropil.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Adachi A, Natesan AK, Whitfield-Rucker MG, Weigum SE, Cassone VM. Functional melatonin receptors and metabolic coupling in cultured chick astrocytes. Glia. 2002;39:268–278. - PubMed
    1. Andretic R, Chaney S, Hirsh J. Requirement of circadian genes for cocaine sensitization in Drosophila. Science. 1999;285:1066–1068. - PubMed
    1. Andretic R, van SB, Greenspan RJ. Dopaminergic modulation of arousal in Drosophila. Curr Biol. 2005;15:1165–1175. - PubMed
    1. Aton SJ, Colwell CS, Harmar AJ, Waschek J, Herzog ED. Vasoactive intestinal polypeptide mediates circadian rhythmicity and synchrony in mammalian clock neurons. Nat Neurosci. 2005;8:476–483. - PMC - PubMed
    1. Awasaki T, Lai SL, Ito K, Lee T. Organization and postembryonic development of glial cells in the adult central brain of Drosophila. J Neurosci. 2008;28:13742–13753. - PMC - PubMed

Publication types

Substances

LinkOut - more resources