American scientists recently discovered that there are "food-related" physiological clocks in animals that can replace light-based master clocks. This discovery helps to explain how animals regulate circadian rhythms to avoid starvation, and shows that by adjusting eating time, humans can better cope with jet lag and night work. Related papers were published in the May 23 issue of the journal Science.
In the lower part of the hypothalamus of the animal's brain, a group of cells called the suprachiasmatic nucleus (SCN) plays the role of the body's main circadian clock. The SCN receives the signal of the day-night cycle via the visual system and transmits the signal to another group of cells called the dorsolateral nucleus (DMH) in the lower part of the hypothalamus. The DMH then organizes the sleep-ejaculation cycle, as well as activity, feeding, and hormones. cycle.
Clifford Saper, chairman of the Department of Neurology at the BDS Medical Center in Boston, USA, said: "When the food is readily available, the system works extremely well. The light signal helps the animal establish a physiology that adapts to the standard day-night cycle. Rhythm.†However, if food is not available during normal awakening, the animal needs to be able to adapt to getting food during regular sleep.
In order to survive, the animal developed a second "food-related" clock. Saper said: "This new clock allows animals to shift their sleep and wake schedules so that they have the opportunity to maximize food discovery."
In the experiment, the researchers used a mouse that inactivated the key gene of the clock (BMAL1) as a test subject, and then placed the gene into a virus vector, achieving the purpose of restoring the function of the clock at only one place in the brain. Through this step-by-step analysis, the researchers revealed the biological clock related to eating.
Saper said: "We found that feeding after the starvation cycle turned on the clock, so it effectively crossed the SCN and hijacked all circadian rhythms into a new time zone, consistent with food acquisition."
Saper said that this discovery is expected to be applied to travelers and shift workers. For example, travelers can adjust their time difference faster by changing their eating time so that their eating clock starts to run. He said: "Fourteen hours of fasting is enough to start the new clock. So, eating nothing on the plane and eating as soon as possible after landing will help you adjust the time difference and avoid some uncomfortable jet lag. â€