Circadian rhythm disorders occur when the body's internal clock, located in the suprachiasmatic nucleus (SCN), is not properly synchronized (entrained) to the 24-hour solar day. Desynchronization of the circadian clock from the light-dark cycle can result in disturbed sleep, fatigue, and impaired performance characteristic of jet-lag and shift-work sleep disorder. In mammals, a subset of photosensitive retinal ganglion cells (RGCs) that contain the photopigment melanopsin transmits photic information to the SCN to entrain molecular, physiologic, and behavioral rhythms to the solar cycle. The inputs, projections, and neurotransmitters of RGCs that express melanopsin will be examined to better understand how light resets the circadian clock. Neuronal tracing and histochemical techniques will be used to determine whether these RGCs receive input from rods and cones, and whether these RGCs project to other brain regions involved in non-visual photic processing. The complement of neurotransmitters in RGCs that convey light as chemical signals will also be determined. Experimental findings will be used to construct a model that describes how light entrains the circadian clock to the solar day, and how uncoupling of the pacemaker from the light-dark cycle leads to circadian rhythm disorders. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31MH067413-02
Application #
6660346
Study Section
Special Emphasis Panel (ZRG1-F02A (20))
Program Officer
Desmond, Nancy L
Project Start
2002-09-15
Project End
2005-08-31
Budget Start
2003-09-15
Budget End
2004-09-14
Support Year
2
Fiscal Year
2003
Total Cost
$28,942
Indirect Cost
Name
Beth Israel Deaconess Medical Center
Department
Type
DUNS #
071723621
City
Boston
State
MA
Country
United States
Zip Code
02215
Gooley, Joshua J; Schomer, Ashley; Saper, Clifford B (2006) The dorsomedial hypothalamic nucleus is critical for the expression of food-entrainable circadian rhythms. Nat Neurosci 9:398-407
Gooley, Joshua J; Lu, Jun; Fischer, Dietmar et al. (2003) A broad role for melanopsin in nonvisual photoreception. J Neurosci 23:7093-106