Why do mice die earlier than people? New discovery of a biological clock

A New York University dentist has discovered a biological clock that links the development of teeth to other metabolic processes. This clock, or circadian rhythm, controls many metabolic functions and is based on the body's daily rhythm, a 24-hour cycle that is crucial in determining patterns of eating, sleeping, and activity. rest, cell regeneration and other biological activities in mammals .

This newly discovered rhythm, similar to the daily rhythm, originates in the brain region that controls body temperature, hunger, thirst, etc., a region of the brain that functions as the main control center of the autonomic nervous system. . However, unlike the daily rhythm, this clock is different in different organisms, such as short and longer species in larger species. Specifically, rats have a 1 day cycle, 6 days ape and 8 days.

New York University dental faculty, Dr. Timothy Bromage, discovered this rhythm when observing the growth ring on the enamel layer, shaped almost like the annual rings on a tree trunk. He also observed related growth patterns in bone tissue, for the first time such growth rhythm was observed on bone.

Three-dimensional images of a piece of femur bone show growth lines corresponding to the circadian rhythm with a repeating cycle every 8 days. The black hole above is the blood vessel. (Photo: Dr. Tim. Bromage)

Its findings at the 37th annual meeting of the American Dental Research Association, Bromage stated, 'Biological rhythms that control the growth of teeth and bones also affect bone size, body size and progress. Metabolic processes, including heart rate and breathing. In fact, this rhythm affects the life of a creature and its life. Therefore, a mouse with a 1/8-time development of bones and teeth will live faster and die sooner. "

Humans are the most different species in this long-term growth rhythm, some people have a 5-day cycle and others up to 10 days. Therefore, people have the largest body size difference among mammals.

Future studies will assess whether there is a link between a slower pace of growth and a growth disorder. Because the autonomic nervous system controls human behavior, future studies will also assess whether the growth rate is related to human behavioral differences.