2006 Fiscal Year Final Research Report Summary
Mechanism of biological clock in mammals: Analysis of regulatory mechanism of
| Project/Area Number |
16380201
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Basic veterinary science/Basic zootechnical science
|
|---|
| Research Institution | University of Miyazaki |
|---|
Principal Investigator |
MURAKAMI Noboru University of Miyazaki, Faculty of Agriculture, professor, 農学部, 教授 (80150192)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NASU Testuo University of Miyazaki, Faculty of Agriculture, Associate professor, 農学部, 助教授 (40108725)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Keywords | Biological clock / Neuromedin U / Neuromedin S / Suprachiasmatic nucleus / Circadian rhythm |
|---|
| Research Abstract |
We identified a novel neuropeptide of 36 amino-acid residues in rat brain as an endogenous ligand for the orphan G protein-coupled receptor FM-4/TGR-1, which was identified to date as the neuromedin U (NMU) receptor, and designate this peptide 'neuromedin S (NMS)' because it is specifically expressed in the suprachiasmatic nuclei (SCN) of the hypothalamus. We examined the role of NMU and NMS on the biological rhythm. The expression of NMU mRNA exhibited a circadian rhythm, with the peak expression in the SCN occurring at CT4-8 h. The two NMU-binding receptors (NMU-R1 and NMU-R2) were also expressed in the SCN Intracerebroventricular injection (ICV) of NMU and NMS induced the expression of Fos protein in the SCN cells and caused a phase-dependent phase shift of the circadian loco motor activity rhythm. This NMU-and NMS-induced phase shift was of the nonphotic type. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed increases in the expression in the SCN of immediate early genes, such as c-fos, NGFI-A, NGFI-B, and JunB. Furthermore, ICV injection of NMU increased the expression of Per1, but not Per2 in the SCN. These results indicate that NMU and NMS may play some important role in the circadian oscillator by exerting an autocrine or paracrine action in the SCN.
|
