American scientists have found mutations in genes that protect older people from dementia. Their appearance in antiquity is associated with infection with infectious pathogens – for example, gonococcus, which causes gonorrhea. Researchers believe that the bacterium helped women live to menopause in their right mind. Thanks to this, they were able to raise grandchildren, writes Naked Science.
The mutation was found in the CD33 gene, a receptor expressed in immune cells. Scientists believe it arose as an adaptation to molecular mimicry gonococcus. Changes in the gene level its interaction with the bacterium, and the immune system can attack it once more.
Parallel to this, mutations in CD33 led to the fact that it allowed the destruction of damaged brain cells and plaques. The higher expression this gene, the better it protects once morest the development of Alzheimer’s disease.
It turns out that by protecting themselves from gonorrhea, ancient people to some extent saved themselves from senile dementia.
Neither Denisovans nor Neanderthals had such a mutation. Therefore, scientists have suggested that it might help the ancestors of people to better adapt to nursing viable offspring. For example, women began to live longer and, becoming grandmothers in their right mind, looked following their grandchildren.
