Thinking is harmful
How Thinking Degrades DNA
Kirill Stasevich, CompulentaThe well–known ironic remark "Thinking is harmful", it turns out, has a serious biological foundation.
Thinking is actually harmful: researchers from the Gladstone Institute (USA) have found that DNA is damaged in active neurons – and the more active the nerve cells, the harder the individual thinks, the more it is damaged.
Scientists put young mice in new cages that were more spacious than the old ones, with new toys and new smells. The animals were given two hours to study and memorize a new territory, after which the level of gamma-H2A protein was measured.X is in their brain. This protein accumulates when double-stranded breaks appear in DNA. According to Lennart Muke, under whose guidance the experiments were conducted, single-stranded breaks in DNA are not uncommon, but double-stranded ones, when two strands in a nucleic acid molecule are torn at once, are already a serious danger and usually accompany some kind of disease. And that's why the authors of the work were very surprised when these "painful" double-stranded breaks were found in the DNA of neurons of absolutely healthy mice. Moreover, as they write in the journal Nature Neuroscience (Suberbielle et al., Physiological brain activity causes DNA double-strand breaks in neurons, with exacerbation by amyloid-beta), mice in new cells had six times more such breaks than those that remained in the old ones.
DNA damage occurred in different parts of the brain, but was especially pronounced in the dentate gyrus, which is believed to be responsible for spatial memory. In other words, the normal activity of a healthy brain turns out to be linked to rather unhealthy molecular events. It turns out that learning and memorization are accompanied by increased damage to DNA and enhanced repair of it (without it, the brain would quickly fail).
Researchers cannot yet explain why neural activity damages DNA. Perhaps this is due to the fact that active neurons generate a lot of free radicals-oxidants, which tear DNA. However, in laboratory experiments with nerve cell cultures, antioxidant preparations did not reduce the number of breaks in the DNA of neurons at all. Scientists believe that there may even be a certain meaning in DNA damage: during learning and memorization, the synthesis of certain proteins is activated, and perhaps damage in DNA and their subsequent repair somehow affect the activity of genes and communication with each other.
All of this may be directly related to neurodegenerative diseases like Alzheimer's syndrome. Most DNA damage is eliminated within a day, but if beta-amyloid is present in neurons, which accumulates in Alzheimer's disease, many DNA damage remains unrepaired.
On the other hand, it is known that mice with embedded human beta-amyloid have abnormal activity of nerve cells, up to epileptic seizures, which, by the way, are also noted in alzheimer's sufferers. If mice are given an antiepileptic drug, then their level of DNA damage decreases. Another interesting fact: it turned out that the absence of tau protein - another protein characteristic of neurodegenerative disease – suppressed the formation of DNA breaks, even if there was a lot of beta-amyloid in the cells.
That is, the harmful effect of proteins that provoke neurodegenerative ailments may be due to the fact that they contribute to the accumulation of damage in DNA. These proteins can either directly affect the DNA repair system, or "overheat" neurons with unnecessary activity, because of which repair machines simply will not have time to patch holes in the genome. But so far these are just hypotheses that, I want to believe, will be tested in the very near future.
Prepared by the Gladstone Institute: Gladstone Scientists Discover that DNA Damage Occurs as Part of Normal Brain ActivityPortal "Eternal youth" http://vechnayamolodost.ru