Scientists have found a way to control the human brain using a protein lurking inside a creature known as'vampire fish' that has lived on Earth for hundreds of millions of years. US scientists used a protein from a lamprey, which is an ancient lineage of jawless fish similar to eel, to turn off brain circuits associated with addiction, anxiety and depression. Researchers took a gene from the protein, called parapinopsin, and found they were able to control it in the way neurons communicate with each other. Parapinopsin also responds to light, allowing scientists use beams of light to turn off the circuit or reactivate it alter reward behaviors - which could lead to brain implants to deliver treatment. Those suffering with addiction, anxiety and depression may have often wished if they could just turn off their brain and the latest discover could soon make that happen.