Affiliations
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Professor,
Psychiatry and Biobehavioral Sciences
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Member,
Brain Research Institute,
Molecular, Cellular & Integrative Physiology GPB Home Area,
Neuroscience GPB Home Area
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Research Interests
Most organisms, including humans, exhibit daily rhythms in their behavior and physiology. In most cases, these rhythms are generated by endogenous processes referred to as circadian oscillators. These oscillators provide temporal structure to an organism?s physiological processes. Nearly all functions of the body show significant daily variations including arousal, cognition, learning, memory, motor performance and perception. This temporal variation obviously plays an important role in the body?s homeostatic mechanisms and has a major impact on the function of the nervous system. Mammals have evolved a set of anatomically discrete cell populations that function as a physiological system to provide temporal organization on a circadian time scale. These structures are commonly referred to as the circadian system and can be localized to a pair of structures in the hypothalamus known as the suprachiasmatic nucleus or SCN. Importantly, when SCN cells are removed from the organism and maintained in a brain slice preparation, they continue to generate 24-hour rhythms in electrical activity, secretion, and gene expression. Previous studies suggest that the basic mechanism responsible for the generation of these rhythms is intrinsic to individual cells in the SCN. In order to function adaptively, these cells must be synchronized to the exact 24 hr cycle of the physical world. The daily cycle of light and dark is the dominant cue used by organisms, including humans, to synchronize their biological clocks to the environment. Therefore, in the simplest case, a circadian system can be modeled as having three components: 1) input pathways by which the environment and other components of the nervous system provide information to the SCN, 2) an oscillator or clock within the SCN responsible for the generation of the daily rhythm, and 3) output pathways by which the SCN provides temporal information to a wide range of physiological and behavioral control centers. The long-term goal of our research program is to understand each of these three components at different levels of organization from systems to molecular. My laboratory uses two strategies to approach this goal. In one, a systems-level analysis is carried out on the effects of genetic and pharmacological manipulations on behavioral rhythms driven by the circadian system. The other strategy examines the effects of these manipulations on the cellular/molecular activity of neural populations that make up this system.
http://www.mrrc.npi.ucla.edu/CColwell/Colwell_Lab_WebPage/page1.htm
Biography
Christopher S. Colwell is a Neuroscientist who has served on the UCLA School of Medicine faculty since he joined the Department of Psychiatry and Biobehavioral Sciences in 1997. He became a Professor in 2008. Dr. Colwell earned his B.S. in Neuroscience from Vanderbilt University in 1985. During this time, he started his research in circadian rhythms under the mentorship of Dr. T. Page. Dr. Colwell earned his Ph.D. in Biology at the University of Virginia in 1991. His thesis work explored the neural mechanisms by which light regulates circadian rhythms. Dr. Colwell continued this line of research during a postdoctoral fellowship at the University of Virginia with Dr. G. Block. A second postdoctoral fellowship was carried out on the topics of motor control and excitotoxicity in the laboratory of Dr. M. Levine at UCLA. Dr. Colwell learned how to utilize imaging techniques to measure calcium levels inside neurons while a visiting scientist in the laboratory of Dr. Konnerth at the University of Saarland, Germany. Since Dr. Colwell's faculty appointment at UCLA, his laboratory's research has focused on understanding the mechanisms underlying circadian rhythms in mammals. Dysfunction in the timing these daily cycles is a key symptom in a number of neurological and psychiatric disorders. Better understanding the basic biology of this timing system should result in new therapies to improve the quality of life of these patients and the people who care for them.
Publications
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