A discipline that combines optics and genetics to enable the use of light to stimulate and control cells in living tissue, typically neurons, which have been genetically modified to respond to light. Only the cells that have been modified to include light-sensitive proteins will be under control of the light. The ability to selectively target cells gives researchers precise control.
Using light to control the excitation, inhibition and signaling pathways of specific cells or groups of cells within the brain has clinical potential, especially in the treatment of neurological disorders. Optogenetics already offers opportunities for basic neuroscience research. The specificity with which researchers can direct expression, along with the ability to have tight, reversible control of the activity patterns of the light sensitive cell(s), provide a sophisticated method to control neural activity. Optogenetics also provides reversible control over cells (when the light is turned off, the cell ceases to respond to it), and allows researchers to measure the effects of their manipulation in real-time.
Optogenetics was first reported in 2005 by Karl Deisseroth, the D. H. Chen Professor of Bioengineering and of Psychiatry and Behavioral Sciences at Stanford University. In 2005 Deisseroth's laboratory, including graduate students Edward Boyden and Feng Zhang, published the first demonstration of the use of microbial opsin genes to achieve optogenetic control of neurons. Deisseroth named this field "optogenetics" in 2006.
In 2016, ongoing efforts to refine optogenetic techniques included work on improving the light sensitivity of the genetically modified proteins.
In addition, better modes of light delivery will be required to improve the accuracy and efficiency of optogenetic strategies. Alternatives under investigation include arrays of separately addressable LEDs that cover brain areas of interest, and infrared illumination systems that can penetrate deep within the dense tissues of the brain.