Christophe P. Ribelayga, Ph.D.
 Research Assistant Professor
Department of Neuroscience
Degree: Neuroscience, University Louis Pasteur, Strasbourg, France
Postdoctoral Training: University of Alabama at Birmingham, AL
Phone: (614) 292-5412
Fax: (614) 688-8742
Email: ribelayga.1@osu.edu
Link to NLM PubMed publications list for Christophe P. Ribelayga(last 10 years)
Research Area:
Retinal neurobiology, Circadian rhythmicity in retinal physiology, Circadian and seasonal rhythm generating systems, modulation of pineal biochemistry. Current Research: The long-term goal of my research is to elucidate the mechanisms by which circadian clocks affect the physiology of the vertebrate retina.
Biological timekeeping is a characteristic of Life. This feature has been shown to rely on endogenous biological clocks, which continue to run in constant environmental conditions (e.g. constant darkness) with periods of approximately 24 h (circadian clocks), and are synchronized to environmental rhythms through external cues. In vertebrates, circadian clocks have been located in countless nervous and non-nervous structures throughout the body. A molecular mechanism of the clock based on a set of genes (the so-called clock genes) and their protein products has been recently identified. Yet, the link between the clock molecular mechanism and physiological overt rhythms remains elusive. The vertebrate retina and its well documented anatomy and physiology and ready access is a tractable model to study the link between the circadian clockwork and physiology. Indeed, a circadian clock is located in the retina, and a variety of biochemical, morphological and physiological processes exhibit circadian rhythms. In addition, the clock genes are expressed in the retina. To date however, the link between the clock genes and retinal physiology remains obscure, although accumulative evidence indicates that a perturbation of circadian rhythmicity in the retina may lead to photoreceptor degeneration. We combine molecular and anatomical approaches together with electrophysiological techniques to: 1) establish the exact cellular (co)localization of the different clock genes in the vertebrate retina; 2) identify the effectors of the retinal clock (e.g. neurohormones such as dopamine, adenosine, melatonin…); and 3) characterize the impact of the clock on electrical activity of specific retinal neurons. Ultimately, this research will provide a clearer and more complete understanding of how circadian clocks modulate retinal physiology and how a perturbation of circadian rhythmicity in the retina leads to physiopathology. Techniques: Electrophysiology: intracellular and patch-clamp recording, tracer injection and cytochemistry. Cellular Biology: cell culture, radioimmunoassay, radioenzymatic assay, protein assay, immunocytochemistry. Molecular Biology: in situ hybridization, RT-PCR, RNase Protection Assay, Northern Blotting. High Performance Liquid Chromatography (HPLC): electrochemical and fluorescence detections.
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