The circadian clock system in the mammalian retina.
Daily rhythms are a ubiquitous feature of living systems. Generally, these rhythms are not just passive consequences of cyclic fluctuations in the environment, but instead originate within the organism. In mammals, including humans, the master pacemaker controlling 24-hour rhythms is localized in the suprachiasmatic nuclei of the hypothalamus. This circadian clock is responsible for the temporal organization of a wide variety of functions, ranging from sleep and food intake, to physiological measures such as body temperature, heart rate and hormone release. The retinal circadian clock was the first extra-SCN circadian oscillator to be discovered in mammals and several studies have now demonstrated that many of the physiological, cellular and molecular rhythms that are present within the retina are under the control of a retinal circadian clock, or more likely a network of hierarchically organized circadian clocks that are present within this tissue. BioEssays 30:624-633, 2008. (c) 2008 Wiley Periodicals, Inc.
Circadian Rhythms and Sleep Disorders Program, Neuroscience Institute. Morehouse School of Medicine, Atlanta, GA, USA. gtosini@msm.edu
Gianluca
G
Tosini
Nikita
N
Pozdeyev
Katsuhiko
K
Sakamoto
P Michael
PM
Iuvone
D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D025461:Feedback, Physiological; D006801:Humans; D008322:Mammals / Q000033:anatomy & histology / Q000502:physiology; D008550:Melatonin / Q000737:chemistry / Q000378:metabolism; D010507:Periodicity; D010786:Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
D015534:Trans-Activators; D056926:CLOCK Proteins; C538943:CLOCK protein, human; D008550:Melatonin