Neurons are not responsible for sleep
Astrocytes are so-called neuroglia cells, a rather complex complex of auxiliary cells of the nervous tissue. They themselves do not conduct nerve impulses. But, as suggested by previous studies, they secrete some chemicals into the space of the neuroglia, including adenosine; a nucleotide that is part of nucleic acids. As it turned out, it is this substance that triggers the sleep mechanism.
The researchers turned off the production of adenosine by astrocytes in experimental animals. To do this, they had to create transgenic mice with the introduced dnSNARE gene, the expression of which blocked the release of adenosine in astrocytes. After that, the scientists deprived the mice of sleep and conducted a study of their brain activity using electroencephalography, as well as behavioral tests.
It turned out that after prolonged sleep deprivation, the mice needed only a short time for compensatory sleep to return to normal. Memory tests of such mice after prolonged artificial insomnia also showed that the mice actually seemed to get enough sleep.
In addition, physiologists were able to determine exactly where adenosine acts on neurons. The fact is that there are several types of surface receptors in nerve cells that can interact with adenosine, but only pharmacological blockade of the A1 receptor in mice has proved effective in combating sleep. Thus, in the hands of scientists turned out to be another link in the chain that sends us to bed every day.
This is the first recorded case of participation of non-neural brain cells in the behavior of a living organism.
According to scientists, the discovery of such an unexpected role of astrocytes will help in the creation of two types of drugs at once – more effective, accurate and safe sleeping pills and drugs that help fight drowsiness.
The scientists' work was published in the journal Neuron on January 29, 2009.
Portal "Eternal youth" www.vechnayamolodost.ru03.02.2009