Rewiring the Brain: Inside the New Science of Neuroengineering
First of two parts.
Dr. Ed Boyden is showing off his lab’s equipment with naked delight. We’ve whizzed
past a laser table, a 3-D printer and some rattling biological shakers, and come to
rest beside a water cutter.
Boyden picks up a piece of scrap metal and demonstrates how the cutter uses a
powerful stream of water and fine bits of garnet (nearly as hard as diamond) to slice
precisely through almost any material. It can be used to build nearly anything. He
pauses, and considers. “We’re probably the only lab in the world that uses a water
cutter to build neural interfaces.”
Boyden directs MIT’s Neuroengineering and Neuromedia Lab, part of the MIT Media
Lab. He explains the mission of neuroengineering this way: “If we take seriously the
idea that our minds are implemented in the circuits of our brains, then it becomes a
top priority to understand how to engineer brains for the better.”
Here, neuroscience is not merely studied, it is applied. Which is why we’re off again,
to see the molecular engineer’s microscope, the viral growing area, and the machine
where they cut micron-thin slices of mouse brains in order to evaluate what changes
they’ve made using the rest of the equipment.
Human beings worked out a few thousand years ago that the brain is where the
action is. Since then we’ve been trying to get it to do what we want it to.
Like a computer, the power of the brain arises out of how the many parts constantly
and quickly talk to each other. But unlike the electrical circuits in a computer, brain
cells aren’t physically connected to one another. Neurons communicate across tiny
empty spaces, called synapses, that lie between the tendrils of neuronal cell bodies.
This almost-but-not-quite touching is what gives them such flexibility as those
connections form and fade throughout our lives.
Most of what we think of as our ability to learn and change comes from the pattern
of those synapses. In a way, history is the story of trying to manipulate those
patterns through learning, faith, love, drugs, food, exercise — in short, anything and
everything. We have spent thousands of years working out indirect ways of changing
the contours of our brains to change the shape of our minds.
Neuroengineers, on the other hand, take a pragmatic and direct approach. They are
trying to change brains by going in and just changing them.
Boyden, a bespectacled professor with a soft smile, speaks rapidly and expansively.
He has been a polymath all his life, plunging into one discipline after another. It’s
hard to imagine there was ever a time when he wasn’t moving.
“Early in life, I wanted to be a mathematician,” he says. He walked the path of the
quantitative universe, studying math, then physics, then electrical engineering, trying
to understand the universe — trying to change it in precise ways. But it was birds
and serendipity that brought him to the messy human brain.
“I decided to go to Bell Labs and learn lasers,” Boyden says, “but the person I
wanted to work with was going home to Germany, so I ended up working with his
neighbor, Michael Fee, who was analyzing how the bird brain generated birdsong.
That experience was my first work in biology or neuroscience.” Boyden had a new
Not long after he found himself in the Stanford University lab of Dr. Karl Deisseroth,
combining his abilities as an engineer with his new calling as a neuroscientist. There,
Boyden was part of a team that invented a new way of controlling brain cells.
Employing molecular biology, genetic engineering, surgery, fiber optics and lasers,
they created a kind of “light switch” which was then used to control a group of