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David M. Raizen, MD, PhD

David M. Raizen, MD, PhD

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Assistant Professor of Neurology
Department: Neurology
Graduate Group Affiliations

Contact information
Dept Neurology
462 Stemmler Hall
415 Curie Blvd
Philadelphia, PA 19104-4283
BA (Biochemistry)
University of Texas at Austin, 1989.
MD (Medicine)
University of Texas Southwestern, 1997.
PhD (Neuroscience)
University of Texas Southwestern, 1997.
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Perelman School of Medicine > Faculty > Search

Description of Research Expertise

Research Interests
The regulation and function of sleep

Key Words: sleep, ecdysis, molting, behavior, amyloid, neuropeptides

Description of Research
Quiescent behavioral states are universal to the animal world with the most famous and mysterious of these being sleep. Despite the fact that we spend one third of our life sleeping, and despite the fact that all animals sleep, the core function of sleep remains a mystery. In addition, the molecular basis underlying sleep/wake regulation is poorly understood.

We use C. elegans as a model system to address these questions. C. elegans offers many experimental advantages including powerful genetic tools as well as a simple neuroanatomy.

Growth of C. elegans from an embryo to an adult is punctuated by four molts, during which the animal secretes a new cuticle and sheds its old one. Prior to each molt the worm has a quiescent behavioral state called lethargus. Lethargus has several similarities to sleep including rapid reversibility to strong stimulation, increased sensory arousal threshold, and homeostatic regulation.

In addition to larval sleep, C. elegans also sleeps during the adult stage, after exposure to an environment that induces cellular stress.

Molecular genetic similarity between C. elegans sleep and sleep in other animals is demonstrated by the identification of signaling pathways that regulate C. elegans sleep in the similar fashion to their regulation of sleep in mammals and arthropods. We have identified new sleep regulators in C. elegans and are currently studying how and in which cells these regulators function.

By studying the purpose and genetic regulation of nematode sleep, we hope to identify additional novel sleep regulators, and to gain insight into why sleep had evolved, a central biological mystery.

Rotation projects
Please see David about possible projects.

Description of Clinical Expertise

Sleep disorders: In particular disorders of sleep regulation and restless leg syndrome.

Selected Publications

Jinzhou Yuan, Jessie Zhou, David M. Raizen, and Haim H. Bau: High-throughput, motility-based sorter for microswimmers such as C. elegans. Lab on a Chip (Impact factor 5.7) 15(13), July 2015.

Yuan J, Raizen DM, Bau HH: The propensity of undulatory swimmers, such as worms, to go against the flow. PNAS (impact factor 9.8) 112, March 2015.

Lenz O, Xiong J, Nelson MD, Raizen, DM, Williams JA: FMRFamide signaling promotes stress-induced sleep in Drosophila. Brain Behavior and Immunity (Impact factor 6.1) 47: 141-148, 2015.

Trojanowski NF, Nelson MD, Flavell SW, Fang-Yen C, and Raizen DM : Distinct mechanisms underlie quiescence during two Caenorhabditis elegans sleep-like states. Journal of Neuroscience (impact factor 6.3) in press, 2015.

Yuan J, Raizen DM, and Bau HH: A hydrodynamic mechanism for attraction of undulatory microswimmers to surfaces (bordertaxis). Journal of the Royal Society Interface (impact factor 3.9) in press, 2015.

Davis EM and Raizen DM: Prolonging apneas in a hospitalized patient – a potential harm of routine medical therapy. Annals of the American Thoracic Society 11(9): 1500-1503, Nov 2014.

George-Raizen JB, Shockley KR, Trojanowski NF, Lamb AL, and Raizen DM: Dynamically-expressed prion-like proteins form a cuticle in the pharynx of Caenorhabditis elegans. Biology Open 3(11): 1139-1149, November 2014 Notes: Article featured on the journal cover.

Nelson MD, Lee KH, Churgin MA, Hill AJ, Van Buskirk C, Fang-Yen C,and Raizen DM: FMRFamide-like FLP-13 neuropeptides promote quiescence following heat stress in Caenorhabditis elegans. Current Biology (Impact factor 9.9) 24(20): 2406-2410, October 2014 Notes: Article discussed in Nature Neuroscience Reviews.

Hill AJ, Mansfield R, Lopez JMNG, Raizen DM,and Van Buskirk C: Cellular Stress Induces a Protective Sleep-like State in C. elegans. Current Biology (Impact factor 9.9) 24(20): 2399-2405, October 2014 Notes: Article discussed in Nature Neuroscience Reviews).

Nagy S, Raizen DM*, Biron D. : Measurements of behavioral quiescence in Caenorhabditis elegans. Methods (Impact factor 3.2) 68(3): 500-507, August 2014 Notes: *Corresponding Author.

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Last updated: 10/05/2015
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