Scientists have discovered an unusual connection between pain and hunger

© Fotolia / photophonieБоль abdominalScientists have discovered an unusual connection between pain and hunger© Fotolia / photophonie

Hunger was one of the most effective ways to suppress chronic pain, not inferior to opiates and other painkillers, say scientists in an article published in the journal Cell.

«We didn’t expect that hunger will somehow affect the perception of pain and no change such a significant way. On the other hand, when we started to monitor the behavior of the mice, we all became clear. Even whether the animal has some kind of wound or injury, it should not suffer pain, and to find the strength to find food and survive,» said amber Alhadeff (Amber Alhadeff), a neurophysiologist from the University of Pennsylvania (USA).

The feeling of pain is one of the most universal and understandable to all living beings of danger signals that the body uses to protect the body from further damage or reckless behavior. Quite a long time, scientists believed that all genders, species, kingdoms and ages feel the pain equally, however, recently revealed that it is not.

For example, two years ago, canadian neuroscientists found that men and women perceive pain different groups of nerve cells, and that chronic pain differently affect their behavior, including the sexual instincts. Such discoveries have forced scholars to think about how pain may affect the perception of the world.

Alhadeff and her colleagues randomly opened one of the examples of such relationships by observing the behavior of mice and their nerve cells that control the sense of hunger and fullness. By studying their reactions to the day fast, neuroscientists have unexpectedly discovered that a lack of food forced a few less rodents to lick and to «babysit» a paw, which they damaged before the start of the experiments.

Having discovered this phenomenon, scientists tried to find the chain of neurons that was associated with the hunger center with the brain’s pain center in the brain of rodents. To do this, they infected some of their neurons with a special retrovirus that caused these cells to forcibly enabled or disabled by irradiation with light, and alternately highlight them.

As it turned out, the discomfort dulled the so-called AgRP-neurons – the cells of a particular part of the hypothalamus, the deep part of the brain that plays the role of the «hunger center». Their forced inclusion completely blocked the sense of pain, even if the mice were fed and do not suffer from lack of food.

«The strength of this effect is that we at first did not believe in what we see, and thought that formalin, which we rubbed the paws of animals, exhausted. Analgesic effect in this case is comparable to the affect on the body morphine and other opiates. Activation of these cells does not cause hunger and other side effects, which could not suppress the pain, but simply to distract the animal,» adds Nicholas Batley (Nicholas Betley), colleague Alhadeff.

As the researchers note, is not yet clear whether this chain of neurons in the human brain and to facilitate its activation to block the feeling of pain. Nevertheless, its discovery and development of drugs acting on these cells may become the first effective method of dealing with chronic pain that will not cause addiction like opiates, conclude the authors.