Area(s) of Expertise
- Behavioral Neurobiology, Circadian Rhythms, Developmental Biology
My research is aimed at understanding the mechanisms and functions of circadian rhythms. Life evolved on a rotating planet under the influence of regular cycles in light and temperature and eventually in the activity of life itself. This has had a profound impact on organisms from bacteria to humans. Twenty-four-hour (circadian) cycles in biochemistry, physiology, and behavior are universal and innate features of living systems affecting functions from the timing of sleep and wakefulness to the daily activation of metabolic enzymes. Circadian rhythms are entrained by light/dark cycles to insure that rhythmic activities occur at appropriate times of day. Artificial light and other aspects of modern life disrupt the normal entrainment of circadian rhythms. The disruption of circadian rhythms has been linked to sleep/wake disruptions, mood disorders, cancer, metabolic syndromes, and reduced immune function.
Although circadian rhythms are an intrinsic property of most cells and are expressed in tissues throughout the body, they are normally coordinated by a “master clock” in the brain, the Suprachiasmatic Nucleus (SCN). The SCN communicates both within the brain and to other organs by as yet unidentified signals. We have worked with mice and hamsters to understand how the coordination among different circadian rhythms is regulated with emphasis on signals between the SCN and other brain areas and on the emergence circadian rhythms during development. Our work involves the analysis of rhythms in whole animal behavior as well as in gene expression in individual tissues, in both adult and developing animals. Identifying the signals that mediate circadian regulation is critical to understanding how the integrity of the system is regulated and how it can become disrupted by environmental conditions or in disease.