Biologists have found a protein that can be the cause of the phantom sense of bitterness

Biologists have discovered a protein that breaks off the molecular signals of bitterness. If there is no this protein in the taste cells, then animals and man can not get rid of the unpleasant aftertaste. Scientists are sure that the absence of an anti-humic molecule can cause phantom sensation of bitterness.

Taste receptors are needed not only to get pleasure from food. The taste of taste is one of the ways to obtain information about the quality, safety and nutritional value of products. The lungs and intestines also taste. But they need such sensations, not for knowledge, but for stimulating appetite and facilitating breathing.

Man and other mammals recognize sweet, piquant (spicy, pungent), bitter, salty and sour taste tones. "When you drink tonic, quinine molecules" include "taste cells that begin to send a signal to the brain that the tonic is bitter," write scientists from US research centers, explaining that the mechanism for informing the brain of bitterness and other taste sensations well studied, it has no white spots. But it is not entirely clear how the activated informative cells "turn off" after the bitter food stopped annoying them.

Biologists explain that the activation of taste cells is associated with an increase in the concentration of calcium ions (Ca ²⁺ ) in the cytosol - the liquid part of the cell content. To the brain no longer "feel" the taste, calcium ions must leave the cytosol of the taste cells.

Molecular biologist Liquan Huang from the Monell Chemical Senses Center and his colleagues decided to deal with the mechanisms of cleansing taste cells from calcium ions. Biologists found that in the receptors that recognize bitterness, too much protein Serca3.

"This molecule is part of the family of Ca ²⁺ -ATPase internal membranes (SERCA). It "confiscates" calcium, driving it into a network of intracellular membranes - the endoplasmic reticulum, "biologists write in an article published today in PLoS ONE. To test whether Serca3 really stops the bitter signals, scientists created mice in the genome that lacked the gene for this protein (Serca3-KO mice).

In the course of the experiment, the mice tried solutions of food chemicals of five taste groups. To do this, researchers for forty-eight hours allowed mice to drink distilled water and a solution of one of the taste chemicals (sugar, salt, quinine and others). After two days the animals were given respite for several days, after which the drinkers with distilled water and another solution of the taste chemical again appeared in the cage. During the experiment, scientists measured the amount of liquid drunk and monitored the behavior of animals

It turned out that mice without Serca3 protein experience a stronger and longer aversion to bitter water than conventional animals. They snorted and spit more and did not go nearer to the drinker longer. "This is due to the fact that they too long feel a bitter aftertaste," scientists explain the results of observations.

Biologists note that aversion to bitter water is noticeable not only in behavior. In experimental mice, the glossopharyngeal nerve reacted more strongly to bitter water than in animals from the control group. Biologists have not detected any significant differences with regard to salty and acidic taste chemicals. But they noticed that the sensitivity of the Serca3-KO mice to sweet and hot taste. As it turned out later, these changes are associated with the compensatory appearance of a related compound - Serca2 protein. By the way, in people with acute perception of bitterness, the taste for sweet and spicy varies.

"Our results explain why people perceive the taste differently," the study authors conclude. - Although this is a fundamental work, it has an applied value. For example, you can develop medicines for people who feel phantom tastes. "

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