Low Temperature Abolishes Human Cellular Circadian Rhythm Through Hopf Bifurcation

This study investigates the impact of low temperatures on human cellular circadian rhythms, revealing that cold exposure can abolish these rhythms in cultured human cells by reducing oscillation amplitude, which is restored upon rewarming. The study identifies this phenomenon as a Hopf bifurcation, supported by a mathematical model of the mammalian circadian clock. Interestingly, human hair follicle cells did not show significant sensitivity to temperature changes, suggesting an evolutionary advantage in maintaining circadian rhythm stability despite environmental fluctuations.