Analyzing the brain of the fly Drosophila melanogaster , Dierk Reiff and his colleagues have found that in one sixth of a cubic millimeter of its brain it has more than 100,000 nerve cells, each with multiple connections to neighboring cells.
To study the functioning of these neurons, the researchers impregnated them with fluorescent markers and discovered that there are certain nerve cells, called L2 cells, that receive information from the photoreceptors in the eyes and react according to increasing or decreasing the intensity of the surrounding light . Based on this "simple" light stimulus, flies are able to calculate in milliseconds the direction of movement around them and send it quickly to the flight control system, to escape at full speed if there is any some threat nearby.
