Stimulating a single nerve-cell circuit among millions in the brain instantly increases a mouse’s appetite for getting to know a strange mouse, while inhibiting it shuts down the same mouse's drive to socialize with the stranger.
Stanford brain scientist and technology whiz Karl Deisseroth, MD, PhD, is already renowned for his role in developing optogenetics, a technology that allows researchers to turn on and turn off nerve-cell activity deep within the brain of a living, freely roving animal so they can see the effects of that switching in real time. He also pioneered CLARITY, a method of rendering the brain - at least if it's the size of of a mouse's - both transparent and porous so its anatomy can be charted, even down to the molecular level, in ways previously deemed unimaginable.
Now, in another feat of methodological derring-do detailed in a new study in Cell, Deisseroth and his teammates incorporated a suite of advanced lab technologies, including optogenetics as well as a couple of new tricks, to pinpoint a particular assembly of nerve cells projecting from one part to another part of the mouse brain. We humans' brains obviously differ in some ways from those of mice. But our brains have the same connections Deisseroth's group implicated in mice's tendency to seek or avoid social contact. So it's a good bet this applies to us, too.
Yes, we'd all like to be able to flip a switch and turn on our own "party animal" social circuitry from time to time. But the potential long-term applications of advances like this one are far from frivolous. The new findings may throw light on psychiatric disorders marked by impaired social interaction such as autism, social anxiety, schizophrenia and depression.From my release on this study:
“Every behavior presumably arises from a pattern of activity in the brain, and every behavioral malfunction arises from malfunctioning circuitry,” said Deisseroth, who is also co-director of Stanford’s Cracking the Neural Code Program. “The ability, for the first time, to pinpoint a particular nerve-cell projection involved in the social behavior of a living, moving animal will greatly enhance our ability to understand how social behavior operates, and how it can go wrong.”
Previously: Lightning strikes twice: Optogenetics pioneer Karl Deisseroth's newest technique renders tissues transparent, yet structurally intact, Researchers induce social deficits associated with autism, schizophrenia in mice, Anti-anxiety circuit found in unlikelybrain region and Using light to get muscles moving
Photo by Gamerscore blog