Brain imaging of people undergoing deep brain stimulation* (DBS) to treat depression is revealing the mechanism behind the effects of DBS, which seems to tune an array of brain regions, not just the area around the electrode, according to researcher Helen Mayberg of Emory University.

Ultimately, the specificity of optogenetics (in which individual neurons are turned off and on with pulses of light) might allow researchers to make far more subtle changes to brain networks.

* Applying rapid pulses of weak current via electrodes to specific brain locations