Recently there’s increasing study and focus on a remarkable approach to manipulating the activity of our brain. Scientists believe it has potential to combat psychiatric disorders like depression, narcolepsy, Parkinson’s and many others. And its source comes from an unlikely place: pond scum.

Let me back up. Two organisms, a single-celled algae and an Archeabacterium have proteins that respond to blue and yellow light. Scientists inserted the genes from these organisms into specific mouse brain cells. During initial experiments in 2007 scientists at Stanford University inserted very a fine fiber-optic—50 micrometers in diameter—into specific cells in the right motor cortex of these mice. Then they flipped on a blue light. Suddenly the mouse started manically running in counterclockwise circles. When they turned the light off, the mouse immediately stopped.

And while blue light causes these brain cells to fire, yellow light stops them. So by using blue and yellow light, scientists are able to speak the language of the brain.

The same researchers showed that this approach—called optogenetics—could return controlled movement to mice suffering from Parkinson’s. Beyond controlling neural firing in the brain, scientists have recently found that by inserting another gene cells will glow green when they fire. That means they can watch the brain in detailed action, a step towards decoding its cryptic signals in order to understand just how our elusive brains work.

—Christie Nicholson