Genetic mechanism: how our internal clocks
A Life / / December 19, 2019
About the internal clock heard everything, but few know how they work. Two groups of scientists from the United States conducted extensive research to understand how our work hours and what is their effect on the body.
Throughout the day we listen to the "ticking" clock inside our body. That's it arouses us in the morning and makes you feel sleepy at night. That it raises and lowers our body temperature at the right time, regulates the production of insulin and other hormones.
Body's internal clock, the same ticks that we feel is also called circadian rhythms.
These rhythms affect even our thoughts and feelings. Psychologists study their effects on the human brain, causing volunteers undergo cognitive tests at different times of the day.
It turned out that morning - this is the best time to perform tasks that require the brain multitasking. If you need to hold several layers of information in your head and process the data efficiently, it is necessary to start to work early in the day. But the second half of the day is well suited for the treatment of simple and clear tasks.
Circadian rhythms have a huge impact on those who suffer from depression or bipolar disorder. People with problems sleeping badly and feel the urge to drink throughout the day. Some dementia patients feel special "decline effect": at the end of the day become aggressive or lost in space and time.
- Sleep and activity cycles are an essential part of mental disorders - says Huda Akil (Huda Akil), a neuroscientist at the University of Michigan. Therefore, neurologists are struggling to understand how our internal clock and the impact they have on our brains. But researchers can not just open the skull and around the clock to watch the cells work.
Several years ago, the University of California donated for research brainWho carefully kept after the donor's death. Some of them died in the early morning, the other - in the second half of the day or night. Dr. Akil and her colleagues decided to investigate whether different brain from one another and a difference of at what point the dead donor dependent.
- Maybe our guess will seem simple, but somehow no one thought of this before, - says Dr. Akil.
She and her colleagues chose brain specimens obtained from 55 healthy people, the cause of whose death was a sudden occurrence such as a car accident. researchers from each brain tissue samples were taken of those shares which are responsible for learning, memory and emotions.
At the time of the death of the donor genes found in brain cells, actively encoded protein. Due to the fact that the brain was quickly saved, the scientists have the opportunity to evaluate the activity of genes in the moment of death.
Most of the genes tested by researchers, showed no regularity in the work during the day. However, more than 1000 genes exhibit diurnal activity cycle. The brain is the people who died in the same time of the day showed the same job genes.
Model activity was virtually identical, so much so that they can be used as a time stamp. To determine at what point the person died, one could almost infallibly, by measuring the activity of these genes.
Then the researchers tested the brains of those donors who have suffered from clinical depression. Here, the time stamp was not just knocked down; it seemed that these patients lived either in Germany, or Japan, but not in the United States.
The results of this work were published in 2013. Researchers from the University of Pittsburgh were inspired by them and tried to repeat the experiment.
"We could not think of before, and a similar study," - says neurologist Colin McClung (Colleen McClung). Dr. McClung and her colleagues were able to check out 146 copies of the brain obtained with donor University program. The experimental results have been published recently.
But team doctor McClung was able not only to repeat the results of the previous experiment, but also get new data. They compared the gene activity patterns in the brain young and old people and found an intriguing difference.
Scientists are hoping to find an answer to the question: why the circadian rhythms of people change as they grow older? After all, when people get older, the activity is reduced, and the rhythms of change. Dr. McClung found that some of the genes that were most active in the daily cycles, to 60 years ceased to be used.
It is possible that some older people no longer produced a protein necessary for the operation of the internal clock.
The researchers were surprised to find that some of the genes included in the activities of daily work only in old age. "It seems that the brain tries to compensate for the shutdown of some other genes work by activating" additional hours ", - said Dr. McClung. Perhaps the brain's ability to create backup circadian rhythms - a way to protect against neurodegenerative diseases.
Switching to spare the internal clock can be used by doctors for the treatment of disorders related to circadian rhythms. Now, researchers are experimenting with animal genes and trying to understand how genes are activated and deactivated the internal clock.
In other words, scientists listen to the "tick" and want to understand: what are we trying to say brain?