We often hear the phrase “sedentary lifestyle” in a negative context, it is spoken of as the cause of poor health or even the onset of illness. But why is a sedentary lifestyle so harmful in reality? I recently came across an article that explained a lot to me.
It is known that physical activity can constructively influence the state of the brain, stimulating the formation of new cells and causing other changes. New research has emerged showing that immobility can also trigger changes in the brain by deforming certain neurons. And this affects not only the brain, but also the heart.
Such data were obtained in the course of a study that was carried out on rats, but, according to scientists, it most likely matters for humans. These findings may help explain, in part, why sedentary lifestyles are so negative for our bodies.
If you are interested in the details of the study, then you will find them below, but in order not to tire you with details, I will tell you about its essence.
The results of the experiment, published in The Journal of Comparative Neurology, show that physical inactivity deforms neurons in one of the brain regions. This section is responsible for the sympathetic nervous system, which, among other things, controls blood pressure by altering the degree of narrowing of the blood vessels. In a group of experimental rats, which were deprived of the ability to actively move for several weeks, a huge number of new branches appeared in the neurons of this part of the brain. As a result, neurons are able to irritate the sympathetic nervous system much more strongly, disrupting the balance in its work and thereby potentially causing an increase in blood pressure and contributing to the development of cardiovascular diseases.
Of course, rats are not humans, and this is a small, short-term study. But one conclusion is clear: a sedentary lifestyle has vast physiological consequences.
It seems to me that after a week spent in the cold, which, unfortunately, is not at all my element and significantly limits my stay in the fresh air and my activity in general, I feel like after an experiment. And I can draw my personal conclusions from this experiment: lack of physical activity has an extremely negative effect on mood and general well-being. ((
More on the topic:
Until 20 years ago, most scientists believed that the structure of the brain is finally fixed with the onset of adulthood, that is, your brain can no longer create new cells, change the shape of those that exist, or in any other way physically change the state of its brain after adolescence. But in recent years, neurological research has shown that the brain retains plasticity, or the ability to transform, throughout our lives. And, according to scientists, physical training is especially effective for this.
However, almost nothing was known about whether the lack of physical activity can influence the transformation of the structure of the brain, and if so, what the consequences might be. So, to conduct the study, information about which was recently published in The Journal of Comparative Neurology, scientists from the Wayne State University School of Medicine and other institutions took a dozen rats. They settled half of them in cages with rotating wheels, into which the animals could climb at any time. Rats love to run, and they have run about three miles a day on their wheels. The rest of the rats were housed in cages without wheels and were forced to lead a “sedentary lifestyle.”
After nearly three months of the experiment, the animals were injected with a special dye that stains specific neurons in the brain. Thus, the scientists wanted to mark neurons in the rostral ventromedial region of the medulla oblongata of animals – an unexplored part of the brain that controls respiration and other unconscious activities necessary for our existence.
The rostral ventromedial medulla oblongata controls the sympathetic nervous system of the body, which, among other things, controls blood pressure every minute by altering the degree of vasoconstriction. Although most of the scientific findings related to the rostral ventromedial medulla oblongata have come from animal experiments, imaging studies in humans suggest that we have a similar brain region and it works in a similar way.
A well-regulated sympathetic nervous system promptly causes blood vessels to dilate or constrict, allowing proper blood flow, so you can, say, run away from a burglar or climb out of an office chair without fainting. But the overreaction of the sympathetic nervous system is causing problems, according to Patrick Mueller, an associate professor of physiology at Wayne University who oversaw the new study. According to him, recent scientific results show that “overactive sympathetic nervous system contributes to cardiovascular disease by causing blood vessels to constrict too hard, too weakly or too often, leading to high blood pressure and cardiovascular damage.”
Scientists hypothesize that the sympathetic nervous system begins to react erratically and dangerously if it receives too many messages (possibly distorted) from neurons in the rostral ventrolateral medulla oblongata.
As a result, when scientists looked inside the brains of their rats after the animals had been active or sedentary for 12 weeks, they found noticeable differences between the two groups in the shape of some of the neurons in that region of the brain.
Using a computer-assisted digitization program to recreate the inside of the animal’s brains, the scientists found that the neurons in the brains of the running rats were in the same shape as at the beginning of the study and were functioning normally. But in many of the neurons in the brains of sedentary rats, a huge number of new antennae, the so-called branches, have appeared. These branches connect healthy neurons in the nervous system. But these neurons now had more branches than normal neurons, making them more sensitive to stimuli and prone to send random messages to the nervous system.
In fact, these neurons have changed in such a way that they become much more irritating to the sympathetic nervous system, potentially causing an increase in blood pressure and contributing to the development of cardiovascular disease.
This discovery is important, says Dr. Müller, as it deepens our understanding of how, at the cellular level, inactivity increases the risk of cardiovascular disease. But even more intriguing about the results of these studies is that immobility – like activity – can change the structure and functioning of the brain.
Sources:
NYTimes.com/blogs
The National Center for Biotechnology Information