Image: Daniele Levis Pelusi / Unsplash
Scientists at Stanford University in the US conducted an experiment, during which they forced the mice to hallucinate, stimulating only a few neurons. This indicates the existence in mammals is not yet known mechanism that prevents the occurrence of false perceptions in response to the noise, i.e., random activity of nerve cells. This publication reports Science Alert.
In the study, neuroscientists inserted into nerve cells in the visual cortex of rodents, two genes. One of the genes encodes a protein that activated the neuron whenever the cage was falling pulses of infrared radiation. A second gene involved in the synthesis of a protein emitting green light upon activation of the neuron. Then the scientists removed part of the skull over the visual cortex, replacing it with a transparent material.
The visual system of rodents stimulated by the images horizontal or vertical line on a white background, the researchers identified neurons that are activated in each case. Mice were then trained to drink water when on the screen appears a vertical line. However, with a substantial reduction in image contrast, the animals ceased to distinguish between the lines and drink. Using a special device, the researchers activated the infrared light exactly those neurons that were responsible for the perception of vertical lines and the mouse again started to drink, even if the image itself was absent.
It turned out that for the formation of in mice a false sense that they see the line, it was necessary to activate all 20 neurons. Because the human brain has 20 billion neurons, it remains unclear how it inhibits hallucinations due to random activity of many neuronal cells.
Video, photo All from Russia.