We huddle together…
The need for carbon dioxide forces naked diggers to maintain self-isolation
African naked diggers are real record holders in animal health, and in the all–around. These small burrowing rodents live for more than three decades without aging and without succumbing to cancer, cardiovascular and neurodegenerative diseases. And recently it turned out that for the normal functioning of the brain, they need ... carbon dioxide.
Article by Zions et al. Nest Carbon Dioxide Masks GABA-Dependent Seizure Susceptibility in the Naked Mole-Rat is published in the journal Current Biology – VM.
The naked digger (Heterocephalus glaber) is unique among animals, primarily due to its longevity: if we had a similar life expectancy, then, taking into account the difference in our size with the naked digger, we would live for 600 years. And these rodents were very resistant to lack of oxygen, without which, as you know, there is no life. So, in oxygen–free conditions, the human brain dies in 10-15 minutes, mice last only a minute, and these "super-rodents" - 18 (!) minutes, after which they fully recover.
This property will not seem so surprising if we turn to the way of life of animals. Colonies of naked diggers actually represent a single "superorganism", like bees and termites. The family, which includes the queen queen, her "husbands" and numerous workers engaged in the extraction of food and other useful activities, lives in a rather cramped underground nest. This lifestyle is associated with significant limitations. In densely populated tunnels, access to oxygen is limited. Although the composition of the air in sparsely populated areas of the underground habitats of naked diggers shows only a slightly elevated level of CO2, it is clear from a number of experimental studies that these animals are adapted to a high concentration of carbon dioxide.
Recently, scientists from the USA and Finland studied in the laboratory the behavioral and physiological reactions of naked diggers to different conditions – in the nest and "on the surface" at "African" temperatures up to 42 °C. It turned out that in the nest, the colonists preferred to spend most of their time in places most rich in carbon dioxide. But, being on the "surface", they demonstrated increased motor activity, culminating in convulsions – a consequence of the so-called hypocapnic alkalosis, a shift in the acid-base balance of the blood.
Apparently, this condition is similar to febrile convulsions that occur at high temperatures in young children, as well as in mice and baby rats (by the way, it is known that because of the "greenhouse" living conditions, naked diggers themselves are not strong in regulating their body temperature). This convulsive activity is explained by the "immaturity" of inhibition processes in the brain, which are mediated by the neurotransmitter gamma-aminobutyric acid (GABA). As a result, the neurons cannot work in concert and are overexcited.
It is known that in humans, the tendency to develop such a condition is associated with a variant of the KCC2 gene responsible for the removal of chlorine ions from the cell. When the KCC2 protein is not active enough, chlorine accumulates inside the cell, disrupting the inhibitory effect of the GABA neurotransmitter. As a result, not only seizures can develop, but also epilepsy, autism and schizophrenia.
The same mutation of the KCC2 gene was found in naked diggers, and a similar mutation was found in African rodents of Damarian sandworms with a similar lifestyle.
Scientists believe that the brain disorders that occur in naked diggers on the "freedom" themselves serve as a unique adaptation to their lifestyle. It literally forces these animals to return to their underground nest, where the stuffy and stale air by our standards, with a high content of carbon dioxide, restores the normal functioning of their nervous system, and at the same time supports the specific social structure of the community.
The results of this work are interesting not only in themselves, but also because they can be used to improve the condition of people with pathologies caused by a mutation in the KCC2 gene.
Portal "Eternal youth" http://vechnayamolodost.ru