Scientists have found that the human body also tracks the natural seasons in a kind of “chemical calendar.” form, writes the BBC.
They are guided by the extension of the day for its transition to the “summer” phase and, accordingly, its shortening for its “winter” form. The researchers made their discovery by analyzing the brains of sheep in different seasons of the year.
They found that the body has a group of 17,000 so-called “calendar cells” in the pituitary gland, which is located at the base of the brain, and releases hormones that control the processes in the body.
“The seasonal clock found in sheep is probably the same for all vertebrates, or at least contains the same parts,” said Professor Dave Burt of the University of Edinburgh. “The next step is to understand how cells store time,” he added.
According to scientists, “calendar cells” have their own binary system, just like computers, and can only exist in one state – “summer” or “winter”. At the same time, the proportion of the two types of cells during the year marks the flow of time in the body.
“It seems that for a short period of time during the year, in the middle of summer and in the middle of winter, they are all in the same phase,” said Professor Andrew Ludon of the University of Manchester.
This annual clock is known as the annual rhythm and is a cousin of the circadian rhythm that keeps us awake at the right time of day. This annual animal model is responsible for migration, hibernation and mating and explains why lambs are born in the spring, for example.
Both clocks – day and year, are controlled by the amount of light. The sleep hormone, for example – melatonin, is produced in larger quantities in winter, because then the days are darker.