Optogenetics is a biological technique that involves the use of light to control cells in living tissue, typically neurons, that have been genetically modified to express light-sensitive ion channels. This allows researchers to turn specific neurons on or off with millisecond precision, providing a powerful tool to study the causal relationship between neural circuits and behavior.
The technique was pioneered in the early 2000s, with key contributions from Karl Deisseroth, Ed Boyden, and others. The discovery of channelrhodopsin, a light-gated ion channel from green algae, was the breakthrough that enabled the field. By inserting the gene for this protein into neurons, scientists could control them with light.
Optogenetics has revolutionized neuroscience, allowing for precise mapping of brain circuits involved in memory, fear, addiction, and movement. It has provided insights into neurological disorders like Parkinson's disease, epilepsy, and depression. While primarily a research tool in animal models, it holds long-term potential for therapeutic applications in humans.