The man , like many animals , circadian activity ( circadian rhythms in the body) is tied to a change in lighting at the alternation of day and night . Working the night shift , prolonged far into the night battle in a computer game , or frequent travel to another time zone – all this confuses our internal biological clock and can lead to depression and mood changes.
Even the natural reduction of daylight in the winter , especially in the northern regions , often causes seasonal affective disorder .
For many years, scientists are trying to learn the basics of the internal biological clock for a person to learn and control it .
In a new article published in the edition of Nature Neuroscience, researchers from Vanderbilt University claim to have found ” the reset button” biological clock .
These experiments were performed on genetically modified mice, which coincided with the biological rhythm of a human, with the difference that has been configured to nocturnal. Thus it was used optogenetic methods to monitor the operation of cells of the nervous tissue with light.
“We found that we can change the periods of sleep and wakefulness animal artificially stimulating with a laser and fiber neurons in the main biological clock. They are located in the area of the brain called the suprachiasmatic nucleus,”- says study leader Douglas G. McMahon.
The neurologist was aware that the rate of occurrence of the pulses in neurons of the suprachiasmatic nucleus is associated with circadian rhythm. Previously it was thought that these signals are the result of the work of the biological clockwork , and can not influence its course. But in the new work , scientists have demonstrated that by acting on nerve cells in the body can cheat and get him to believe that the day and night reversed.
To control the activity of neurons in mice in their DNA biologists introduced gene responsible for the synthesis of light-sensitive proteins. Then, very thin optical fibers, conducted directly into the animals’ brains, the cells covered the laser to activate or suppress their activity.
Of course in it’s present form, this approach can not be used in humans. But the researchers believe that in the future when it will be easy and safe to enter any desired genes into the cells of an adult organism, and also used for lighting miniature implants, such therapy becomes possible.
“The main conclusion is that the frequency of the pulses in the suprachiasmatic nucleus is not a consequence of circadian rhythms as we previously thought , but a full key component of this system – says McMahon . – We still have to learn a lot about how our internal clock .” Now a new approach is being tested in rodents , which, like some people , in anticipation of the spring suffering seasonal affective disorder .