Halloween ghosts and goblins may be our early warning that THE holiday season is here, raising our stress levels in preparation for gift shopping, cooking, cleaning, relatives, financial pressure . . .
The flight or fight response, our body’s way to prepare us to combat danger and keep us alive:
- You breathe faster
- Your heart rate increases
- Your blood pressure increases
- Your pupils dilate
- The blood supply to your skin decreases
- Your immune system shuts down
Just in time for Halloween . . . scientists have identified a new hormone that is part of the stress response. It’s a protein called osteocalcin secreted by bone and is involved in triggering the body’s reaction to stress
“Gerard Karsenty, a physician and geneticist at the Columbia University Irving Medical Center, set out to investigate calcification a hardening of bone. In his study of this he eliminated osteocalcin from mice. While that did not change calcification as he had thought, the affected mice did not breed well and had excess fat.”
“Osteocalcin was in the blood of the mice, so Karsenty decided to see if it was a hormone. It was, and was involved in metabolism, fertility and muscle function, and maybe in brain development and thinking. He and others working on osteocalcin wondered why bone would produce a hormone. They thought perhaps bones evolved to help animals escape danger . . . . If so, bones may be part of the fight or flight response.”
Researchers . . .”found that mice without osteocalcin had a much lower fight or fight response, including less of an increase in heart rate, less increase in blood glucose, and less of a rise in temperature-all part of the physiological fight or flight response. This confirmed that osteocalcin played a role in the response.
“As they continued to learn about osterocalcins role, they thought that what it was doing was activating the sympathetic part of the autonomic nervous system This part of the autonomic nervous system is what triggers the fight or flight response. But injecting the hormone into the blood stream did not activate the sympathetic nerve, which was a surprise.”
“What was happening was the parasympathetic part of the autonomic nervous system, which triggers the “opposite” rest and digest response (which come into play when there is no threat), was affected-and it was suppressed.”
So what osteocalcin does is turns off the parasympathetic autonomic nervous system (ANS) –and allowing the sympathetic ANS to take over and start the flight or fight response.”
“The notion that the parasympathetic nervous system is mediating the effects of osteocalcin on stress is a very interesting finding,” says James Herman, a neuroscientist at the University of Cincinnati, “I think what that means is that the way we currently understand stress is too simplistic.” He says that other chemical messengers may also play a role.”
“Karsenty’s team has also learned that stimulating part of the amygdala increases osteocalcin in the blood.”
Not all scientists are convinced of this work, and it will need to be replicated by others to be sure. Maybe we’ll know more by next Halloween.