Effects of photoperiod on the expression of food anticipatory activity in mice: implications to the food- and light-entrainable circadian oscillators

• Grant number: 13/24740-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: March 24, 2014
• End date: March 23, 2015
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Gisele Akemi Oda
• Grantee: Danilo Eugênio de França Laurindo Flôres
• Supervisor: Shin Yamazaki
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Texas Southwestern Medical Center, Dallas (UT Southwestern), United States
• Associated to the scholarship: 11/24120-0 - A lab, field and computer study of the synchronization of circadian rhythms in the subterranean rodent tuco-tuco (Ctenomys aff. knighti), BP.DR

Abstract

Doing the right thing at the right time of the day is important for survival, hence most living organisms present 24-hour (daily) variations in their activities and physiology. In many cases these daily rhythms are sustained even in artificial constant conditions of the laboratory, due to endogenous clock mechanisms which generate rhythmicity, with periods close to the 24 hours of the environment. Therefore endogenous daily rhythms are denominated circadian (circa-24-hour) rhythms and the underlying mechanisms are called circadian oscillators. Synchronization of circadian oscillators to the 24 hours of environmental day depends on external signals perceived by the organism. For instance, the daily light-dark cycle and the daily cycle of food availability each entrain (synchronize) a different circadian oscillator in the body. We intend to verify how the light-entrainable oscillator (LEO) and the food-entrainable oscillator (FEO) behave in mice subjected to different combinations of light and food regimens. The protocol will consist of time restricted feeding under light-dark cycles with different photoperiods (proportions of light and dark). Daily rhythms of running-wheel activity will be recorded in wild-type mice as indirect measurements of the motion of the circadian oscillators, with general nocturnal activity as marker of the LEO and food anticipatory activity (FAA) as and emergent output of the FEO. Moreover tissue explants form transgenic PER2::LUC mice will be recorded ex-vivo for their luminescence rhythmicity as a tool to assess more directly the motion of central and peripheral circadian oscillators in the body. This is one of the first studies to systematically explore daily food synchronization in different photoperiods. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FLORES, DANILO E. F. L.; BETTILYON, CRYSTAL N.; YAMAZAKI, SHIN. Period-independent novel circadian oscillators revealed by timed exercise and palatable meals. SCIENTIFIC REPORTS, v. 6, FEB 24 2016. (13/24740-3)

FLORES, DANILO E. F. L.; BETTILYON, CRYSTAL N.; JIA, LORI; YAMAZAKI, SHIN. The Running Wheel Enhances Food Anticipatory Activity: An Exploratory Study. FRONTIERS IN BEHAVIORAL NEUROSCIENCE, v. 10, JUL 5 2016. (13/24740-3)