Measurement of transcription activity in freely moving mice: Ultradian rhythms and their physiological roles
Description: In freely moving mice, clock gene expression, continuously recorded by luciferase reporter from the suprachiasmatic nucleus (SCN), exhibits ultradian rhythms in addition to the circadian gene expression rhythm. Since the ultradian periodicities were similar in three clock genes, we hypothesized the common mechanisms generating ultradian rhythms within or near the SCN. In the present study, we aimed to find out the common mechanisms underlying these rhythms.We found that the ultradian oscillation originated not in the SCN but in the paraventricular nucleus and subparaventricular zone using the co-culture system and calcium imaging. Glutamate and GABA are involved in generating ultradian rhythms. Using an optical fiber system for measuring bioluminescence continuously, we measured Per1-luc and Bmal1-ELuc expression rhythms and found that two rhythms were transiently uncoupled after phase-delaying light pulse. We further confirmed the two rhythms can be separable in culture system.
Amount: ¥3,640,000
Funding type: research
Funder scheme: Grant-in-Aid for Challenging Exploratory Research
Start date: 2015-04-01
End date: 2018-03-31
Investigator: Sato HONMA (lead)
Institution: Hokkaido University
Funded outputs count: 15
Funder award ID: 15K12763
OpenAlex ID: G3441621987