New Bolton Center Kennett Square, PA
Emergencies & Appointments:
Ryan Hospital Philadelphia, PA


Diplomate, American College of Veterinary Internal Medicine
Contact Information:
3800 Spruce Street
Suite 112

Molecular basis of sleep regulation and function

Drosophila; mutagenesis; sleep-like rest; behavioral genetics

Behavioral, gene expression profiling, and biochemical assays to characterize correlates of states of arousal in Drosophila; mutagenesis to identify genes involved in sleep-like rest homeostasis; drug testing and mutagenesis for novel mechanisms of wake promotion.

After decades of studying physiology and anatomy of sleep and an animal model of sleep apnea (the English bulldog), I have turned my attention to a simpler model-Drosophila. I showed, using behavioral, pharmacological, and molecular approaches, that Drosophila's rest state has sleep-like properties. We have since used this model organism to show that the cAMP-PKA-CREB signaling pathway is involved in rest regulation as well as its well-known role in Long-Term Memory consolidation. This role is conserved in mice. The research program is rapidly expanding to use the Drosophila model to discover genes involved in rest homeostasis using comprehensive mutagenesis as well as the candidate gene approach. We are also collaborating with other researchers in the Center for Sleep and Respiratory Neurobiology to characterize the biochemical profile of rest and waking in flies. We are also using wake-promoting drugs whose mechanism is poorly understood as a probe to identify the genetic basis of rest and waking in flies.

Williams JA., Sathyanarayanan S., Hendricks JC., Sehgal A. Interaction between sleep and the immune response in Drosophila: a role for the NFkappaB relish Sleep 30: 389-400, 2007.

Koh K., Evans JM., Hendricks JC., Sehgal A. A Drosophila model for age-associated changes in sleep:wake cycles.[see comment] Proceedings of the National Academy of Sciences of the United States of America 103: 13843-7, 2006.

Hendricks JC. Broadening the public perception of veterinarians: can we keep what we've got while transforming ourselves? Journal of Veterinary Medical Education 33: 593-4, 2006.

Hendricks JC. Shaking up sleep research Nature Neuroscience 8: 703-5, 2005.

Hendricks JC. Mining the mouse mutant goldmine for sleep phenotypes.[comment] Sleep 28: 389-91, 2005.

Hendricks JC., Sehgal A. Why a fly? Using Drosophila to understand the genetics of circadian rhythms and sleep Sleep 27: 334-42, 2004.

Hendricks JC. Invited review: Sleeping flies don't lie: the use of Drosophila melanogaster to study sleep and circadian rhythms. [Review] [170 refs] Journal of Applied Physiology 94: 1660-72; discussion 1673, 2003.

Hendricks JC., Kirk D., Panckeri K., Miller MS., Pack AI. Modafinil maintains waking in the fruit fly drosophila melanogaster Sleep 26: 139-46, 2003.

Hendricks JC., Lu S., Kume K., Yin JC., Yang Z., Sehgal A. Gender dimorphism in the role of cycle (BMAL1) in rest, rest regulation, and longevity in Drosophila melanogaster Journal of Biological Rhythms 18: 12-25, 2003.

BS (Biology/Psychology) Yale University, 1974

VMD, PhD (Veterinary Medicine) University of Pennsylvania, 1980