A new technique for controlling the brain: optogenetics and its potential for use in research and the clinic

The recent development of optogenetic techniques has generated considerable excitement in neuroscience research. Optogenetics uses light to control the activity of neurons which have been modified to express light-sensitive proteins. Some proteins, such as channelrhodopsin, are cation channels that produce depolarization of neurons when illuminated. In other cases, neuronal activity can be inhibited through illumination of proteins, such as the chloride pump halorhodopsin, that hyperpolarize neurons. Because these proteins can be selectively expressed in specific cell types and/or in specific locations, optogenetics avoids several of the non-specific effects of electrical or pharmacological brain stimulation. This short review will explain the physiology of this technique, describe the basic and technical aspects of the method, and highlight some of the research as well as the clinical potential of optogenetics.