Per2 appears to be important for period determination in the SCN, while Per3 participates in timekeeping in the pituitary and lung.
Previous studies have demonstrated that the FEO is anatomically distinct from the SCN and that FAA is observed in mice lacking some circadian genes essential for timekeeping in the SCN.
Then there is the scandal involving CityTime, a system that was supposed to streamline employee timekeeping in the city.
Further Questions for Discussion: -Do you think that New York City's annual ball drop is the "greatest single moment of public timekeeping in the world"?
To address the problem of slowed timekeeping in the pressure head of the inflow water clock, Zhang was the first in China to install an additional tank between the reservoir and inflow vessel.
Furthermore, these data corroborate the placement of BK activity downstream of clock-gene mediated timekeeping in the SCN.
According to the model of timekeeping in the SCN, the Period (Per) genes are important elements of the transcriptional/translational feedback loops that generate the endogenous circadian rhythm.
Third, Npas2-deficient mice display mostly normal wheel-running activity [27] but take longer to acquire FAA [37], suggesting that NPAS2 is not essential for timekeeping in the LEO, but is important for acquisition of food entrainment in the FEO.
The stability of circadian timekeeping in the face of fluctuating internal as well as external environments is likely to confer organisms with adaptive advantages (Daan, 2000).
The disparate behavior in the circadian mutant animals, however, implies that the contribution of distinct clock proteins to this cognitive process extends beyond that of local timekeeping in the brain.
