Speaker: Dr. Mary Cheng Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Canada "Genes to Behaviour": The Genetic Basis of Circadian Rhythms in Mice. An internal timekeeping mechanism — the "circadian" clock — has arisen in nearly all organisms that allows them to adapt their physiological and behavioral processes to a cyclic 24-hr world. In mammals, the master circadian clock is situated in the suprachiasmatic nucleus (SCN), a bilateral structure within the hypothalamus that generates autonomous rhythms and is exquisitely sensitive to the resetting effects of environmental light. While much is already known about the molecules that constitute the core clock and that are essential for endogenous rhythmicity, the cellular mechanisms that underlie the process of entrainment—i.e. the ability of light (or other external cues) to reset the phase of the clock—remains unclear. The ERK/MAPK pathway is a key regulator of light-induced clock entrainment, and both upstream regulators (e.g. Dexras1) as well as downstream effectors (e.g.microRNA-132) of ERK activation have been shown to modulate the entrainment process. This talk will discuss the role of MAPK signaling and microRNAs in the entrainment process.