Université de Strasbourg

Regulation of retinal clocks

Light regulation of retinal clocks : from cell to visual function

USIAS Fellow: Marie-Paule Felder-Schmittbuhl

Living organisms have developed endogenous mechanisms for time-tracking in accordance with the period of Earth rotation around its axis that allow life adaptation to the day/night cycle. This is based on circadian clocks (~24 h period), a sort of molecular pacemakers housed in virtually every cell in vertebrates, and which govern the timely organization of behavior, cellular and physiological functions around the day/night cycle. At the level of organisms, these clocks work in a hierarchical manner, conducted by a “central” clock located in the hypothalamus. The retina holds a special place in this network, since it is required for synchronization to the day/night cycle, by detecting and encoding environmental light intensity and informing the central clock about the time of day. The retina also harbors a circadian clock that times its physiology over 24 h and allows optimization of visual function in an environment which light intensity can vary over one billion-fold between night and day. We have been characterizing, since a few years, the downstream molecular processes and the tissue-level organization of the retina circadian clock. We showed that the retina contains a network of several oscillators and our project, in collaboration with the laboratory of Dr Dkhissi-Benyahya (Institut Cellule Souche et Cerveau, INSERM U846, Lyon), aims at understanding how light impacts on these clocks to synchronize retina functions to the 24 h cycle.

Investissements d'Avenir