This is a citation of an outside article. Gravyday is not responsible for its content. Original URL below. What social distancing does to a zebrafish brain Scientists discover a neuropeptide that reflects the current state of a fish's social environment Researchers have discovered a brain molecule that functions as a 'thermometer' for the presence of others in an animal's environment. Zebrafish 'feel' the presence of others via mechanosensation and water movements -- which turns the brain hormone on.(more)