• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

2007 Fiscal Year Final Research Report Summary

Morphological approach to the light entrainment mechanism of the circadian clock

Research Project

Project/Area Number 18590198
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field General anatomy (including Histology/Embryology)
Research InstitutionKinki University

Principal Investigator

NAGANO Mamoru  Kinki University, SCHOOL OF MEDICINE, ASSISTANT PROFESSOR (80155960)

Co-Investigator(Kenkyū-buntansha) SHIGEYOSHI Yasufumi  Kinki University, SCHOOL OF MEDICINE, PROFESSOR (20275192)
FUJIOKA Atsuko  Kinki University, SCHOOL OF MEDICINE, ASSOCIATED PROFESSOR (30077664)
HAYASAKA Naoto  Kinki University, SCHOOL OF MEDICINE, ASSISTANT PROFESSOR (80368290)
ADACHI Akihito  SAITAMA UNIVERSITY, GRADUATE SCHOOL OF SCIENCE & ENGINEERING, ASSOCIATED PROFESSOR (20351588)
Project Period (FY) 2006 – 2007
KeywordsSCN / Per1 / Per2 / Prokineticin2 / light resetting / circadian rhythms / Kallmann syndrome / clock gene
Research Abstract

Nocturnal light induces Perl and Per2 genes, which leads to resetting of the circadian clock in the suprachiasmatic nucleus (SCN), the mammalian circadian center. We investigated the light resetting mechanism of their circadian clocks. By using in situ hybridization technique, we found that Perl is used for the advance of the clock and Per2 is used for the delay. Next, in mammals, light is the primary environmental signal used to synchronize endogenous rhythms to the environment. Daylength, or photoperiod also affects many physiological events such as locomotor activity, sleep-wake rhythms, temperature and hormonal secretion. We examined the effects of photoperiod on the daily expression of Perl gene in the SCN. We suggested that the change of photoperiod affected not only in the VLSCN that has rich projection from the retina but also in the DMSCN that is absent from the direct retinal projection. Also, we observed that desynchronization underlies the multicell-level amplitude decrease in the rat suprachiasmatic nucleus induced by critical light pulses.
Using in situ hybridization methods, we investigated the localization of Prokineticin (PK2) and prokineticin receptor 2 (PKR2) in the rat SCN. PK2 mRNA-positive neurons were scattered in both the dorsomedial and ventrolateral SCN. In contrast, PKR2 mRNA-containing neurons were clustered in the dorsolateral part of the SCN. Then, to examine the role of PKR2 in the SCN, we created PKR2-gene-disrupted mice (Pkr2(-/-)). Phenotypic analysis indicated that Pkr2(-/-) mice exhibited hypoplasia of the OB. In addition, the Pkr2(-/-) mice showed severe atrophy of the reproductive system. In the Pkr2(-/-) mice, Immunohistochemical analysis revealed that gonadotropin-releasing hormone neurons were absent in the hypothalamus in the Pkr2(-/-) mice. The phenotype of the Pkr2(-/-) mice showed similarity to the clinical features of Kallmann syndrome.

  • Research Products

    (8 results)

All 2007 2006

All Journal Article (6 results) (of which Peer Reviewed: 3 results) Presentation (2 results)

  • [Journal Article] Melanopsin-dependent photo-perturbation reveals desynchronization underlying the singularity of mammalian circadian clocks2007

    • Author(s)
      Ukai H., et. al.
    • Journal Title

      Nature Cell Biology 9

      Pages: 1327-1334

    • Description
      「研究成果報告書概要(和文)」より
    • Peer Reviewed
  • [Journal Article] Melanopsin-dependent photo-perturbation reveals desynchronization underlying the singularity of mammalian circadian clocks.2007

    • Author(s)
      Ukai H., et. al.
    • Journal Title

      Nature Cell Biology 9

      Pages: 1327-1338

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Distinct localization of prokineticin 2 and prokineticin receptor 2 mRNAs in the rat suprachiasmatic nucleus2006

    • Author(s)
      Masumoto KH., et. al.
    • Journal Title

      Eur J Neurosci. 23

      Pages: 2959-2970

    • Description
      「研究成果報告書概要(和文)」より
    • Peer Reviewed
  • [Journal Article] Abnormal development of the olfactory bulb and reproductive system in mice lacking prokineticin receptor PKR22006

    • Author(s)
      Matsumoto S., et. al.
    • Journal Title

      Proc Natl Acad Sci U S A. 103

      Pages: 4140-4145

    • Description
      「研究成果報告書概要(和文)」より
    • Peer Reviewed
  • [Journal Article] Distinct localization of prokineticin 2 and prokineticin receptor 2 mRNAs in the rat suprachiasmatic nucleus.2006

    • Author(s)
      Masumoto KH., et. al.
    • Journal Title

      Eur J Neurosci. 23

      Pages: 2959-2970

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Abnormal development of the olfactory bulb and reproductive system in mice lacking prokineticin receptor PKR22006

    • Author(s)
      Matsumoto S., et. al.
    • Journal Title

      Proc Natl Acad Sci U S A 103

      Pages: 4140-4145

    • Description
      「研究成果報告書概要(欧文)」より
  • [Presentation] Clock gene daily expression in the suprachiasmatic nucleus is differentially affected in the dorsomedial and ventrolateral regions by photoperiod2007

    • Author(s)
      Nagano M., et. al.
    • Organizer
      2nd World Coongress of Chronobiology
    • Place of Presentation
      東京
    • Year and Date
      20071100
    • Description
      「研究成果報告書概要(和文)」より
  • [Presentation] Clock gene daily expression in the suprachiasmatic nucleus is differentially affected in the dorsomedial and ventrolateral regions by photoperiod2007

    • Author(s)
      Nagano M., et. al.
    • Organizer
      2nd World Coongress of Chronobiology
    • Place of Presentation
      Tokyo
    • Year and Date
      20070000
    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 2010-02-04  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi