The button to switch the main biological clock of the brain can serve as a means of treating seasonal affective disorder, as well as reducing the negative impact of night shift work on human health.
The scientists' discovery is described in the February 2 issue of Nature Neuroscience.
"We have been able to change sleep/wake rhythms in animals by artificially stimulating neurons in the master biological clock located in the area of the brain called the suprachiasmatic nucleus (SCN) using a laser and optical fiber", – told Douglas McMahon – professor of biology and lead author of the study.
Until now, neuroscientists believed that the frequency of firing of impulses by SCN neurons depends on the activity of the biological clock. It did not occur to them that changing the level of activity of neurons could affect the functioning of this clock.
However, researchers at Vanderbilt University have shown that stimulating and inhibiting neurons in the SCN, which models their levels of daytime and nighttime activity, can reset the biological clock.
The study was conducted on mice. Neuroscientists have found that the mechanism of the mouse biological clock is almost identical to the human one, except that the biological clock of mice is set to a nocturnal lifestyle.
Scientists have used optogenetics to control the firing rate of SCN neurons. This technology allows you to insert a gene that expresses optically sensitive proteins into target cells so that they react to light.
"This allowed us to take control of the biological clock neurons for the first time" – scientists rejoice.
The project used two types of genetically modified mice. Neurons in the brain of one species of mouse contained an optically sensitive protein that stimulates neuron activity when exposed to light. And the neurons of the other half of the mice contained a protein that suppresses the activity of neurons under conditions of light exposure.
Of course, scientists have not yet developed a precise approach to solving this problem in humans. However, the fact that the frequency of firing of impulses by SCN neurons is a key element of circadian rhythm makes it clear that the mechanism of the biological clock needs to be studied further.
Source estet-portal.com
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