Nematodes do not lose their memory after freezing
Scientists have proved that during cryopreservation
organisms retain long-term memory
SLY_G, Geektimes
Researchers Natasha Vita-Mor from the American University of Modern Technologies and Daniel Barranco from the Department of Cryobiotechnology of the Spanish University of Seville proved for the first time that the use of cryonic technologies does not destroy the long-term memory of the simplest multicellular organisms. The test subjects were nematode worms Caenorhabditis elegans (Natasha Vita-More and Daniel Barranco, Persistence of Long-Term Memory in Vitrified and Revived C. elegans, Rejuvenation Research 2014 – VM).
C. elegans is a model organism popular among scientists. These are the first multicellular creatures whose genome was completely decoded (this happened at the end of the last century). An adult worm 1 mm long consists of about 1000 cells, and has a nervous system of 302 cells. Its functioning is fully described, so it is convenient to use it to study the mechanisms of motion control, signal transmission via a neural network, chemotaxis (the motor reaction of microorganisms to a chemical stimulus), etc.
Experiments with cryonics, i.e. deep cooling of organisms with an eye to their further recovery and return to life have been conducted since the middle of the last century. In 1967, the first person was cryonized, and in 2011– the creator of the cryonics concept, Robert Ettinger, was also cryonized. But it's one thing to freeze the body, and another to bring it back to life in one piece.
There are technologies of so-called "suspended animation" or, more precisely, suspended animation, when organisms are able to survive for several hours without a heartbeat without harm. These technologies are being worked out to save the victims, for example, to give them a chance to live to a remote hospital. But recovery after a long-term deep freeze remains the fate of the future.
Although there are optimists already now. There are several organizations in the world offering cryonic freezing services for people after death, in the hope that someday in the future they can be revived, and, for example, cured of an incurable disease today.
In modern cryonics, simple freezing is not used – in this process crystals appear in the water, destroying tissues. Instead, scientists use rapid freezing, known as vitrification, in which the liquid turns into an amorphous solid like glass. Cryoprotectors are also involved in the process – auxiliary substances that protect tissues.
The researchers used olfactory chemical imprinting as memory tests. Worms are able to distinguish odors, and if, for example, any chemical substance is associated with food, they will subsequently react to the presence of this substance and look for food. An adult worm is able to remember smells for several hours, and newly born ones can remember smells for up to five days thanks to imprinting (imprinting) – the effect of long-term memorization of information in newly born organisms.
Ducklings, growing up and forming in the egg, remember the voice of the mother duck and run to it; chickens from birth run after any moving object; nematode worms have been instilled with attachment to benzoin aldehyde. Then the next day they were carefully frozen, kept in this state for two weeks and thawed again. After that, the scientists were convinced that the worms had not forgotten the delicious smell of aldehyde and aspired to it no worse than those whom the scientists did not freeze at all.
The results of experiments with worms. Experimental groups from s1 to s10,
vertically – the number of worms that found food.
- s1 – untrained (without imprinting) and not frozen
- s2 – trained, but not frozen
- s3 – untrained and frozen
- s4 – trained and frozen with cryoprotector
- s5 – untrained and vitrified with cryoprotector
- s6 – trained and vitrified with cryoprotector
- s7 – untrained and frozen with cryoprotector
- s8 – trained and frozen with cryoprotector
- s9 – untrained and slow frozen with cryoprotector
- s10 – trained and slowly frozen with cryoprotector
Of course, the brain of higher mammals is much more complex than that of a worm, both quantitatively and qualitatively. For example, there are about 86 billion neurons in the human brain. But the confirmation that cryonics preserves memory in worms gives hope that this is in principle possible in more complex organisms.
Portal "Eternal youth" http://vechnayamolodost.ru25.05.2015