Related Experiment Videos
The mammalian retina as a clock
Gianluca Tosini1, Chiaki Fukuhara
1Neuroscience Institute, Morehouse School of Medicine, 720 Westview Dr. SW, Atlanta, Ga 30310-1495, USA. tosinig@msm.edu
Cell and Tissue Research
|July 12, 2002
Summary
Vertebrate retinas possess an autonomous circadian clock, influencing daily physiological rhythms. This review explores retinal rhythmicity and its underlying molecular mechanisms, highlighting potential differences from the central circadian pacemaker.
Area of Science:
- Neuroscience
- Chronobiology
- Molecular Biology
Background:
- Vertebrate retinas exhibit daily physiological, cellular, and biochemical rhythms.
- These rhythms persist under constant conditions, indicating endogenous circadian control.
- An autonomous circadian clock has been confirmed in vertebrate retinas, including Xenopus laevis and mammals.
Purpose of the Study:
- To review current knowledge on retinal rhythmicity in vertebrates.
- To investigate the mechanisms controlling circadian rhythms in the retina.
- To compare the retinal circadian clock with the central circadian pacemaker.
Main Methods:
- Review of existing literature on retinal circadian rhythms.
- Analysis of molecular techniques identifying core circadian clock genes.
- Comparison of gene expression profiles in the retina and suprachiasmatic nuclei.
Main Results:
- The retinal circadian pacemaker is located in the photoreceptor layer in Xenopus laevis and chickens, but its location in mammals is undetermined.
- Core circadian clock genes are expressed in the retina.
- Retinal clock gene expression shows a different 24-hour profile compared to the central circadian pacemaker.
Conclusions:
- The retina harbors an autonomous circadian clock.
- Molecular differences may exist between the retinal clock and the central circadian pacemaker in the hypothalamus.
- Further research is needed to fully elucidate the mechanisms of retinal circadian control.