Scientists have developed an off switch for the brain.
About ten years ago researchers studying how the brain functions introduced a technique known as 'optogenetics', by which individual neurons could be switched 'on' simply by using light.
That gave scientists a powerful new way to study who thoughts and memories are made deep inside the brain, using nothing except dim pulses of light.
Unfortunately what it didn't give them was an equivalent way to turn off neurons in the same way, meaning that their studies into the circuits that control behaviour - and occasionally misfire - were limited in one direction.
Now thanks to two separate studies researchers are able to silence neurons as well as activate them.
One of the new methods comes from Karl Deisseroth at Stanford University, who helped develop the original technique. He was able to show how changing 10 of the amino acids in the optogenetic protein could reverse the tool and allow them to "apply a brake in any specific circuit with millisecond precision", according to Thomas Insel, director of the National Institute of Mental Health.
The other technique by scientists at Humboldt University of Berlin is similar, to our inexpert eyes, but relies on modifying different amino acids.
The hope is that using these techniques researchers may be able to develop treatments for patients with brain diseases or conditions caused by misfiring neurons. By turning off those malfunctioning parts of the brain with light, it might be possible to surgically target problem areas with relatively little intrusion.
At least, it might one day. As MIT Technology Review explains there are many more issues to overcome. Still, it's a positive step and an intriguing new area of research.