The Brain Research Institute at the University of Notre Dame in Washington has named genes that evolve to “make” mice find stimulants and avoid encounters with predators. A paper describing the work has been published in the scientific journal Nature. During the tumultuous evolution of primates, which were replaced by rats and mice, prosthetic nerve cells gave rodents the ability to know where food was. Thus monkeys acquired the ability to distinguish sharp rocks from sharp turns, and afterwards the ability to avoid a collision with a wall or a wall with sharp edges. This knowledge helped the animals avoid danger and allowed them to explore new territories. The scientists chose associations consisting of repetitive sequences, offering food as a stimulus. Researchers were guided by the current understanding that neurons and proteins can change under the influence of electrical stimuli, which are most often electric field, light, heat, magnetic field, ultrasound, radio waves or sound waves. As a result of evolution, clusters of molecules emerged at the boundaries of nerve cells, which caused the formation of contacts between neurons, leading to the emergence of new schemes of visual communication. By testing selected mouse neurons, the scientists found that the associations changed 26,000 times depending on the stimulus received. It turned out that for rodents this was not a random occurrence, but a pattern. Although the mice were able to interact with the rats through smells and sounds, they also interacted with rodents that had been trained to find food. “When we inject rats with various stimulants, we are very likely to stimulate rodents as well, but unlike those same mice, we have figured out which neurons are involved in making the associations. We showed for the first time that, all other things being equal, mice trained to find food reacted to it and avoided collisions, while rats that were not exposed to such stimuli did not react at all,” said James Klepp of the Brain Research Institute. The research could be used to develop better methods of assessing brain function and to use this knowledge to treat various diseases associated with nerve cell death.
