Once again, life gets closer to Star Trek.
In mammals, the pathways that connect the photoreceptors on the surface of the cone cells to the electrical signal that is sent to the brain are made up of a complex chain of protein interactions. In many single-celled organisms however, the electrical signal is directly activated when light hits the receptor–light changes the shape of the receptor allowing charged molecules to flow through the cell membrane, activating an electrical signal. Volker and his colleagues replaced the complex mammalian protein cascade with just such a light-activated channel from Natronomonas pharaonis, an extremophile archaea found in salty, alkaline African lakes. Amazingly, it worked.
More at Oscillator, a blog by Christina Agapakis.