Circadian rhythms adaptively respond and synchronize to light cues, and neuropeptides are emerging as important players in this light response pathway. One such neuropeptide, vasoactive intestinal peptide (VIP), appears to modulate light responses in the master circadian pacemaker of mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus. The purpose of the proposed studies is to gain a detailed understanding of how VIP-ergic signaling synchronizes the SCN to light. Experiments have been designed to answer the following questions: ls VIP critical for transmission of light-based information across anatomically localized and chemically-defined SCN subregions? Is it required for the gating of light responses in the SCN? Does lack of VIP affect electrical properties of individual SCN neurons? Does VIP regulate electrical responses to light-like phase shifts? Is this regulation anatomically heterogeneous? Are these effects temporally regulated?

Public Health Relevance

Using mice with genetic knockout of VIP, we will study gene expression and electrophysiology in the SCN to determine the specific role of VIP in light-based signaling. Not only will these experiments help clarify the role of this neuropeptide, it will also improve our understanding of how SCN neurons communicate with each other in the mammalian circadian system. In addition to the direct benefits for human health, knowledge from these findings may be extended to our understanding of how neuropeptides modulate sensory signals in other neural systems as well.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS063666-02
Application #
7755822
Study Section
Special Emphasis Panel (ZRG1-F02A-H (20))
Program Officer
Mitler, Merrill
Project Start
2009-01-01
Project End
2010-12-31
Budget Start
2010-01-01
Budget End
2010-12-31
Support Year
2
Fiscal Year
2010
Total Cost
$30,761
Indirect Cost
Name
University of California Los Angeles
Department
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Itri, Jason N; Vosko, Andrew M; Schroeder, Analyne et al. (2010) Circadian regulation of a-type potassium currents in the suprachiasmatic nucleus. J Neurophysiol 103:632-40