Snails in chocolate

According to the Internet, dark chocolate is one of the useful products on the planet. It reduces blood pressure and prevents atherosclerosis; helps regulate blood sugar and strengthens tooth enamel; full of antioxidants; improves mood; Wrong mind and excites memory. However, it is not as easy to convince to reliably verify the benefits of chocolate as it seems. The same memory, for example, is a complex phenomenon, and chocolate is a multicomponent product. It would be nice to study the influence of each of its components, and on some simple model.

One of the convenient objects for researching memory is Lymnae stagnalis . Ken Lukowiak, professor of the Institute of the Brain of the University of Kalgary (Canada), has been working with him for many years. Employees of the Lubkovyak laboratory teach snails to keep the breathing hole closed (pneumatic). Usually, the ponds breathe through the skin with oxygen dissolved in water, but they have lungs, and they sometimes rise to the surface to swallow the air through the respiratory hole. In experiments on the study of the memory of the ponds are placed in water with a low oxygen content. Naturally, they climb over the wall of the aquarium into the air, but there Professor Lukovyak with a wooden stick awaits them there. Each snail, which opened a pneumatic stroke, he lightly knocks with this stick along the edge of the hole. The force of the blow was measured so that the alarmed pond man shuts the pneumatic, but does not hide into the sink. After waiting a little, the snail makes a new attempt to inhale, and again gets a wand. After a half -hour training L. Stagnalis It is absorbed that it is better to keep the handle on the castle, and open it much less often. And scientists have to add different substances to the water and observe how they affect the Uralkin memory, that is, how the frequency of opening the respiratory opening changes and what time she remembers the learned lesson. This simple and understandable system allows us to quantify the influence of each factor, in addition, the closing and opening of the respiratory opening is controlled by a single neuron, and it is convenient to observe the changes taking place in it.

Dark chocolate is glorified by many components; The researchers decided so far to focus on one, flavonoid epicatekhin, which, supposedly, will protect from a stroke, and from diabetes, and even from cancer. This flavonoid is present in cocoa, green tea and red wine. True, he is bitter, so manufacturers often extract him from cocoa and chocolate, but there is an epicatechin in dark chocolate. The student Ken Lukovyak Lee Froson suggested to check the influence of this substance on Ulitkin's memory. He picked up a suitable concentration of a substance, 15 mg per liter of water, which approximately corresponds to the concentration of epicatechin in the body of a person who has eaten a small chocolate, and does not affect the behavior of snails. In oxygen -dining water, they open with the same frequency with a pneumatic and breathe in the air of an equal time that in the presence of an epicatechin, without it. The substance in this concentration also does not affect the motor activity of the snails. After making sure of this, the researchers began to study the influence of Epicatechin on the memory of the priest.

After one half -hour training in pure water with a reduced oxygen content, the snails are less likely to open the breathing hole, but the learned skill is kept from them for no more than three hours. After a day, they no longer remember anything and open with a pneumost with the same frequency as before training, about nine times in half an hour. But in water with epicatechin, the ponds develop a long -term memory: after three hours, and a day after training, they try to breathe air only 5-6 times.

In order to develop a long -term memory in L. Stagnalis , in normal conditions, two sessions with an hourly interval are needed, then the resulting skill will remain for a day. After two lessons, in the presence of Epicatechin, the princes remembered all 72 hours.

But the advantages of the flavonoid are not exhausted, it not only helps to remember, but does not allow you to forget. There is such a special training for forgetting. After the skills are learned and fixed, they are again planted in hypoxic water, but they no longer knock on the respiratory hole. Three sessions of forgetting were held with the ponds: an hour after the test for long -term memory, an hour later and after 24 hours. Already after the second training, the snail in ordinary water is more often opened with a pneumatic stroke, and after the third they return to the original, minib level, 9 breaths in half an hour. But the “chocolate” ponds, even after three training, did not forget anything. They still tried not to open with a perist. Therefore, Epicatechin really helps to strengthen long -term memory. Training for memorization and forgetting in his presence leads to the fact that the snail remembers longer and forgets worse.

Over the years of research, Ken Lukovyak and his group made a long list of factors affecting the memo: the presence of different substances in water, such as potassium chloride or Cairomones secreted by the predator, rapid heating or cooling. All this acts on the Osfradiy, the chemosensor body of the pond, which reacts to a wide range of stimuli. Scientists cut the nerve connecting the Osfradii with the central nervous system, that is, in fact it was turned off. When the snails recovered after the operation, it turned out that long -term memory in the presence of Epicatechin was developed just as effectively.

Researchers suggested that this flavonoid interacts directly with neurons responsible for long -term memory. In the near future, they hope to unravel the special mechanism of the action of Epicatechin, especially since it is easier to do this on the ponds than on any other object, since the neuron initiating the opening of the pneumostoma is also necessary for the formation of long -term memory. Researchers believe that it is on him that Epicatechin acts. In general, Canadian scientists are very satisfied with themselves, since their article, as they say, is the first message about the action of Epicatechin as a memory of invertebrates and about the special mechanism of its action. In addition, dark chocolate cheers up, even one of its components.

Natalia Reznik

Fruson L., Dalesman S. and Lukowiak K. (2012) A Flavonol Pressent in Cocoa [( -) Epicatechin] Enhances Snail Memory. J.​ Exp . Biol . 215, 3566–3576.