How Optogenetics work

“Optogenetics” is a new field that combines molecular biology with light stimulation to allow researchers to have precise control over the behaviour of a cell, populations of cells, or even a whole animal. The term optogenetics comes from the joining of two fields: using genetic tools to target light-sensitive proteins to very specific regions within a cell, or to populations of specific cells within a network, and using optical stimulation (light in the UV to the IR wavelengths) to then activate those very selectively targeted proteins (or other probes). It is a very useful emerging technology, and scientists hope to be able cure diseases like Parkinson's disease with it.

The technology is based on the movement of negative ions in the nerve cells, across the cellular membrane. The balance of these ions inside and outside of a cell, and the potential of the membrane, contribute greatly to whether or not the neuron fires an action potential. Action potentials are central to communication between neurons. Therefore, if we can control the movement of those ions, we can control the cells excitability and how and when it communicates (fires action potentials) with other cells in a network.

The key here is that only the cells (such as the dopamine neurons that are dying in Parkinson’s disease) where you genetically target these proteins will be under the control of the light (leaving other cells to function normally). Even more profound is that the technique does not only apply to researchers that want to control ion channels, optogenetics is also being used with other proteins and molecules to modulate very specific signalling pathways such as those that control protein dynamics.