(by Carey Goldberg, WBUR, May 23, 2011) I was remarking upon the truly astonishing line-up of luminaries attending Rep. Patrick Kennedy’s major brain conference in Boston today, launching an initiative that aims to take on the brain as a challenge on the scale of JFK’s drive to the moon 50 years ago. “It’s just about everybody who’s anybody,” I said — all the names of federal agency leaders and high-profile scientists I’d covered for years on the brain beat.
Yes, said another attendee, “They really brought out all the rock stars of brain science.”
So call me a groupie, but I homed in on one particular scientist whose work I’ve admired from afar but never covered: Dr. Karl Deisseroth of Stanford. He leads work that many see as a real game-changer in brain science. His best summary: “The combination of genetics and optics to achieve gain and loss of function.” My best simplification: You engineer neurons so that, say, green light turns them on, red light turns them off. Green light: scared. Red light: Not scared any more.
Many at the Kennedy conference have noted that the brain is frustratingly hard to experiment on, stuck as it is inside the skull and endlessly complex. Optogenetics lets us effectively turn things in the brain off and on, to test hypotheses, figure out how ciruits work and someday, perhaps, fix them.
Actually, for mice, that day may already have come. Karl Deisseroth’s team showed this spring that they could apparently reduce the anxiety of a mouse by manipulating it optogenetically. The Times reported earlier this month:
Treating anxiety no longer requires years of pills or psychotherapy. At least, not for a certain set of bioengineered mice. In a study recently published in the journal Nature, a team of neuroscientists turned these high-strung prey into bold explorers with the flip of a switch. The group, led by Dr. Karl Deisseroth, a psychiatrist and researcher at Stanford, employed an emerging technology called optogenetics to control electrical activity in a few carefully selected neurons.
First they engineered these neurons to be sensitive to light. Then, using implanted optical fibers, they flashed blue light on a specific neural pathway in the amygdala, a brain region involved in processing emotions.
And the mice, which had been keeping to the sides of their enclosure, scampered freely across an open space.
Obligatory disclaimer: Manipulating circuits in mice is a long way from doing it in humans. But that’s clearly an aim. Speaking at the conference today, Karl noted that he still sees patients as a psychiatrist, and had worked as a VA psychiatrist earlier in his career. He knows all too well that anxiety is hugely common and that many drugs work poorly or carry side effects. It’s known that a brain region called the amygdala is involved in fear, he said, but what about an anti-anxiety circuit?
It is too intertwined with other circuits for easy conventional testing, “but optogenetics has allowed us to do that and actually find that there is a built-in anti-anxiety circuit that’s fast, precise and potent lying within the seat of anxiety itself.”
“This is an example of how we can now come to a causal understanding of what’s involved not only in disease but in resolution of disease,” he said.
Stay tuned for more of this. The journal “Nature” called optogenetics the “method of the year” for 2010. The journal Science has called it a breakthrough. Perhaps the best indicator of all: Karl notes that optogenetics tools are now at work in some 1,000 labs around the world.
Here’s hoping we’ll someday be able to turn on the blue anti-anxiety light ourselves…