Imagine if cells had a surface receptor that could function as an on-off switch which could be manipulated by two light frequencies.  This is the concept researchers at Washington University in St. Louis are developing by putting a G-protein transgene into white blood cells.  This transgene, responsible for vision in optic nerves, can be activated with a laser, causing the cells to move along a pathway.  A future goal is to make islet cells sensitive to on-off insulin production.  MORE