2011 Fiscal Year Final Research Report

Role of dams and light as a zeitgeber during brain development

Research Project

Project/Area Number	22791030
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Embryonic/Neonatal medicine
Research Institution	The University of Tokushima
Principal Investigator	SAKATA Hiromi 徳島大学, 大学院・ヘルスバイオサイエンス研究部, 講師 (50294666)
Project Period (FY)	2010 – 2011
Keywords	概日リズム / 深部体温 / 脳発達 / 同調因子
Research Abstract	To discuss the mechanism of the transition of circadian rhythm from immature to mature shape, we assessed the circadian rhythm of deep body temperature and Per1 expression in rat pups. The timing of suckling acutely affected pup' s body temperature, and the daily rhythm of Per1 expression in the SCN of pups entrained the timing of suckling(or food intake), as well as that in the liver, but not like that in the adult SCN. Thus, we concluded that the timing of suckling(or food intake) is a more important zeitgeber for the pup' s SCN than light/ dark condition. Rats, which inverted SCN rhythm by restriction of feeding time during the postnatal period, showed a significant increase in body weight, hyperactivity, and delayed entrainment with the light/ dark cycle.