Somehow a mass of cells networked together, and called a brain, is able to control almost every aspect of your body and retain all of the information of you, but sometimes these cells misfire. When this happens the result can be very debilitating, such as Parkinson's disease and epilepsy. Fortunately there is new research coming that should be able to effective treat these illnesses, and a tool for those treatments, as reported by the Optical Society of America, has recently been developed.
This tool looks like a comb with teeth about the size of a human hair, but along those teeth are ports to let light out. By implanting the device in the brain, it is possible to use the light signals to activate or deactivate specific, special brain cells. Similar devices have been made before, but this is the first 3D device, which will enable it to operate on entire circuits, potentially. There is a catch though as neurons do not naturally respond to light, but using gene therapy proteins can be added to specific types of cells to make them responsive.
This technology is part of optogenetics, a relatively new field of research that deals with using light to trigger specific effects in the body. Already many scientists are working in this field to better understand how the brain works by looking at what neurons are actually required to activate for certain processes, and which are just passively mimicking others.