Turn on a Light, Turn off a Neuron

PHOTO: Mario D’Amore

An MIT neuroengineer has discovered a way to genetically modify neurons so that their activity can be temporarily silenced using specific colors of light. The technique, which so far has only been tried on mice, takes advantage of a protein (named Arch) which is expressed by the modified neurons when the animals are exposed to rays of yellow-green light. When the proteins are expressed, they pump protons across the cell membrane, alter the neuron’s voltage, and stop it from firing.

In theory, the discovery (which is strangely beautiful, even in the absence of practical applications) could someday be used to treat disorders, such as epilepsy, that are caused by the overactive firing of neurons in certain parts of the brain. It’s also an extraordinarily finely-tuned tool for safely and selectively turning off brain activity, so researchers can learn what different regions of the brain do.

For more, check out the MIT news release or the group’s website.