“A Constellation of Information About Life”
Neuroscientist Edward Boyden wants to know what is happening in the circuitous networks of the brain when thoughts and emotions are in process. He has been working for years on new technologies for close examination of brain functions, and he recently unveiled a new tool called expansion microscopy. He got some of the ideas from diapers.
In a recent Ted Talk Boyden, a father of two young children, notes baby diapers can swell enormously when water is added, “an experiment done by millions of kids every day.” Disposable diapers are cleverly designed, he explains, with an industrial polymer that promotes expansion when they get wet.
Boyden is an associate professor of biological engineering and brain and cognitive sciences at MIT, where is also leads the synthetic neurobiology research group at the MIT Media Lab and the McGovern Institute for Brain Research.
The brain is incredibly complex and dense, posing multiple challenges for researchers. Very specialized cells called neurons are connected in networks, joined together by junctions called synapses that exchange chemicals and allow neurons to communicate, Boyden said. “In a cubic millimeter of your brain,” he told the TED audience, “there are about100,000 of these neurons and maybe a billion of those connections…if you could zoom in to a neuron….what you’d see are thousands and thousands of kinds of biomolecules, little nanoscale machines organized in complex 3D patterns, and together they mediate those electrical pulses, those chemical exchanges that allow neurons to work together to generate things like thoughts and feelings.”
If the brain could be made much bigger, Boyden and colleagues mused, all those connections and interactions could be observed and mapped in three dimensional detail. Boyden has pioneered technological tools to try and discover which specific neurons in the brain govern specific kinds of behavior and emotion. An MIT news story says Boyden’s group, working with the University of Vienna, recently developed a system that can generate 3D movies showing the simultaneous activities of the all parts of the brains of small animals. In an absorbing Edge.org discussion, Boyden explained that researchers at Caltech used one of his group’s technologies to discover specific neurons associated with aggression in the brains of mice. When those neurons deep in the brain were activated by pulses of light, the mice attacked anything near them, even if it was only a rubber glove. He says an MIT colleague also discovered that activating certain brain cells with light could make the mouse recover a rewarding memory.
In an extraordinary presentation, illustrated by artist’s graphics and video, Boyden showed a brain tissue sample infused with the polymer. The specimen had been treated with a chemical that loosened the molecules from each other, and when water was added, and the sample massively expanded and the polymer chains moved apart, taking brain tissue biomolecules with them. In an accompanying technological wonder, the scientists were able to distinguish different kinds of biomolecules with tags of glowing dyes in different colors. Scientists could see individual molecules in the 3D structure of the tissue.
The goal, Boyden said, is to make the invisible visible, to take tiny and obscure things and “blow them up until they’re like a constellation of information about life.” Ultimately, he said, new detailed insights about the brain could help understand and treat such diseases as Alzheimer’s, epilepsy and Parkinson’s as well as yielding clues about what makes us human.
Steven Johnson, in his book Where Good Ideas Come From, describes how some brilliant breakthroughs arise from what he calls “the adjacent possible,” a concept from biology introduced by Stuart Kauffman. Ideas, Johnson writes, are works of bricolage, in which some old or perhaps little unnoticed item or notion is jiggered into a new shape by someone seeking solutions for something else. So a neuroscientist’s curiosity about diapers could provide a part of the inspiration for the path-breaking brain research technologies