Dr. Evans' Research Site

Nearly every cell in your body contains a clock that tracks time of day. These circadian clocks program daily rhythms in behavior and physiology to ensure that biological processes occur at the right time of day. In mammals, the circadian system is a collection of biological clocks regulated by a master clock within the brain, known as the suprachiasmatic nucleus (SCN). As the master clock, the SCN controls clocks located throughout the brain and body so that they are optimally timed relative to one another and the external environment. Recent work indicates that disrupted clock function is linked to a wide variety of health disorders, including depression, learning deficits, cardiovascular disease, obesity, and cancer. Our laboratory investigates the functional organization of the circadian system in mammals, with the ultimate goal of gaining mechanistic insight that can be used to develop new therapeutic approaches for these health risks.

Towards this end, we focus on several key questions:

• How do SCN neurons communicate with one another?
• How does the SCN control other tissues of the body?
• How is the circadian system altered by changes in the environment (e.g., shiftwork, jetlag, seasons) and during disease states (e.g., addiction, neurodegeneration)?
• Are changes in clock function directly linked to pathology?
• What intrinsic and extrinsic factors increase the flexibility of the circadian system?

Selected Publications

• DellaPolla A, Kloehn I, Pancholi H, Callif B, Wertz D, Rohr KE, Hurley M, Baker K, Hattar S, Gilmartin MR, Evans JA (2017). Long days enhance recognition memory and increase insulin-like growth factor 2 in the hippocampus. Scientific Reports, 7:3925.
• Azzi A, Evans JA, Leise T, Myung J, Takumi T, Davidson AJ, Brown SA (2017). Network dynamics mediate circadian clock plasticity. Neuron, 93:441-450.
• Kloehn I, Pillai S, Officer L, Klement C, Gasser PJ, Evans JA (2016). Sexual differentiation of circadian clock function in the adrenal gland. Endocrinology, 157:1895-904.
• Evans JA (2016). Collective timekeeping among cells of the master circadian clock. J Endocrinology, 230(1):R27-49.
• Evans JA, Suen TC, Callif B, Mitchell A, Castanon-Cervates O, Baker KM, Kloehn I, Baba K, Teubner BJ, Bartness TJ, Ehlen JC, Paul KN, Tosini G, Leise TL, Davidson AJ (2015). Shell neurons of the master circadian clock coordinate tissue clocks throughout the brain and body. BMC Biology, 13(1), 43.
• Evans JA, Leise TL, Castanon-Cervantes O, & Davidson AJ (2013). Dynamic interactions mediated by non-redundant signaling mechanisms couple circadian clock neurons. Neuron, 80(4), 973-983.
• Evans JA & Davidson AJ (2013). Health consequences of circadian disruption in humans and animal models. In Prog Mole Biol Transl Sci, 119:283-323.