Christopher S. Colwell
The central goal of our research effort is to understand the molecular, cellular, and systems-level mechanisms that underlie the generation of circadian rhythms and their regulation by light. Our most recent work utilizes calcium imaging and electrophysiological techniques to study synaptic communication in the suprachiasmatic nucleus (SCN). This cellular/molecular analysis is combined with a systems-level analysis of the effects of genetic and pharmacological manipulations on circadian rhythms in behavior. This integration of cellular/molecular and systems-level analysis is central to the approach we take to address research questions. A variety of evidence suggests that the cells in the SCN are responsible for the generation of 24-hour (circadian) rhythms in organisms. Importantly, when these cells are removed from the organism and maintained in a brain slice preparation, they continue to generate 24-hour rhythms in the dish. We use this brain slice preparation in combination with an optical analysis of cell function. Our results indicate that cells in the SCN express a daily rhythm in resting calcium with levels peaking during the day. In addition, these cells show a daily rhythm in their response to stimulation from other cells with peak changes in calcium observed during the night. The presence of this rhythm is important because intracellular calcium plays a critical role in determining a cell’s function by controlling such processes as secretion and gene expression.
Contact Info
Department of Psychiatry and Biobehavioral Sciences
Mental Retardation Research Center
University of California, Los Angeles
760 Westwood Plaza
Los Angeles, CA 90024
Phone: (310) 206-3973
FAX: (310) 206-5060
Email: ccolwell@mednet.ucla.edu