Scientists have found that the hormone that secrets the skeleton of mice and people is responsible not only for metabolism and muscle function, but also for the reaction to fear, EurekAlert reported.
When a person or animal is afraid, special organs - the adrenal glands - release a large amount of adrenaline into the bloodstream and it improves the functionality of muscles and stimulates the nervous system. However, even adrenal mice experience a similar effect during stress. Scientists have suggested that there is another hormone that responds to fear.
Osteocalcin, a hormone that secretes the skeleton helps regulate metabolism, muscle function during exercise and the ability to conceive.
To test whether Osteocalcin really works like a hormone of fear, scientists scared mice, shocked them and forced urine to smell their natural enemies, foxes - and then measured the level of Osteocalcin in the blood of animals. Similarly, circulating levels of bioactive osteocalcin rose in humans exposed to stress from public speaking and cross examination.