Is it really that time of year again already? We’ve reached the end of another exciting twelve months for neuroscience, so let’s look back like we did in 2012, 2013 and 2014, and relive the year’s most mind-blowing moments in brain research.
2015 feels like a year in which stages have been set. We haven’t seen any wild new areas of research burst onto the scene. Instead, a few crucial new techniques have quietly created a kind of cliffhanger—a setup for some truly earth-shaking discoveries within the next few years. Keep an eye on all these technologies. Seriously. You heard it here first.
Here they are: the breakthroughs that are paving the way for next year’s neuroscience headlines.
5. The “Brain-to-Text” Decoding System
Over the past few years, neuroscientists have done some very strange things with Big Data. Now that we’re able to digitally track brain activity with higher precision than ever before, and we’ve also got digital copies of everything from books to films to photos, we can easily break down patterns in our brains—and on our screens—into patterns of ones and zeroes, and we can set powerful computers to search for connections between those patterns. Those kinds of connections have led to software that can reconstruct video clips from the brain activity of the person watching them, or predict which fictional character a person is reading about, based on what their brain is doing. The latest generation of software, designed by a team lead by Tanja Schultz at KIT, can reconstruct an entire spoken sentence based on the brain activity of the person who’s speaking. “Why would we need to decode spoken sentences from brain activity?” you might ask. One obvious use would be for people who suffer from paralysis, stroke or dementia, who may be able to think clearly but have trouble forming words. And could there be applications for people trapped in comas, too?
4. Laser-Transmitted Neural Codes
This one’s a little involved, but just stay with me for a couple sentences here. Our neurons (nerve cells) communicate by firing patterned bursts of electricity to each other. For the past few years, scientists have been triggering neurons to fire by using tiny lasers—this is called optogenetics, and it’s like something out of a sci-fi film. Researchers have already used optogenetic lasers to turn memories on and off, to implant false memories, and even to control fear at the cellular level. Problem is—believe it or not—these lasers are not very precise. Technicians just kind of point them at the neurons they want to target, pull the trigger and hope for the best. But this January, a team led by Michael Hausser of University College London launched a revolution in optogenetics—a revolution that almost nobody has been talking about, but one that’s quietly turning the field upside down. Hausser’s team found a way to record firing patterns from specific clusters of nerve cells, then play those patterns back to targeted groups of cells, on command, using a laser array. This is like the difference between a loudspeaker that plays a random noise, and an earbud that plays a song of your choosing right into the ear of the person you specify. We’re still a long way from decoding the “neural code” itself—but thanks to Hausser and his team, we’re one big step closer to seeing how our neurons respond when we send them coded messages in their native language.
3. Wirelessly Controlled Mouse Brains
Mouse brains aren’t all that different from human brains, which means mice get subjected to all kinds of weird neuroscience experiments. Researchers have digitally transferred memories between the brains of two mice. They’ve “copied and pasted” emotions like fear from one memory to another. They’ve even directly changed mice’s minds, or controlled where they walk, through electronic signals. And with the help of a device invented this year by Ada Poon and her friends at Stanford, they’ll now be able to do all this wirelessly. This noninvasive device sits atop a mouse’s head, and sends tiny pulses of laser light into the mouse’s brain. Some of the mouse’s neurons have to be genetically engineered, in advance, to fire in response to pulses of laser light—and when those neurons get the signal, they set off chains of neural activity throughout the mouse’s brain and body. Using this system, scientists can theoretically do any of the weird experiments they’ve already been doing on mouse brains—except now they can do them wirelessly, with a device the mouse doesn’t even seem to notice. This lets the mouse go about its business in a natural way, giving researchers a clearer view of mouse behavior—and how their experiments impact that behavior.
2. Self-Organizing “Brain Balls”
They’re only five millimeters across. They grow from stem cells, in petri dishes, until they’ve sprouted multiple layers of nerve cells that signal to each other in complex patterns. Their creators, led by Sergiu Pasca at Stanford, are calling them “human cortical spheroids,” or hCSs. Everyone else is calling them “brain balls.” Researchers have been growing vaguely brain-like globs of tissue for a few years now. A team in Japan grew a 3D cell culture that looked and worked sort of like a cerebellum; a team in Australia grew some tiny bundles of brain-ish matter. These new brain balls, though, are the best in the bunch right now. They live longer, grow to greater complexity, and function more like tiny bits of brain tissue than any other brain balls in the world. When the team started growing them from neural stem cells, they were hoping for little networks of neurons. What they got, instead, were sheets of neurons that self-organized into multiple layers, along with support cells called astrocytes, which are crucial to human brain function. Groups of these neurons fire together in synchronized dances of electrical pulses, much like in real brains. Nobody’s saying these little balls can think or feel—but they’re definitely doing something interesting.
1. A Paraplegic Who Can Walk
The phrase “miracle of medicine” gets thrown around a lot. Every new technique that saves a life is undeniably important, but it’s not often that a breakthrough genuinely makes you sit back and say, “Whoa. That’s like something out of the Bible.” This year, a team led by Zoran Nenadic and An Do at the University of California, Irvine brought us exactly that kind of breakthrough. They attached an electroencephalograph (EEG) device to the head of a man who’d suffered from spinal cord damage, and had been completely paralyzed from the waist down for five years. They connected the EEG device to a set of electrodes, which they stuck near the man’s knees. The EEG device recorded electrical signals from the man’s brain—and when he imagined moving his legs, the device transmitted those signals to the electrodes, which fired electrical pulses into his leg muscles, triggering them to move on cue. With the help of this device—along with some external support to take the weight off his weakened legs—the man walked 12 feet across the room. Of all the neuroscience stories I covered this year, this is the only one that brought me to tears. The man’s face is blurred out in all the press photos, but it’s not hard to imagine his expression.
Thanks to all of you who’ve stuck with us for a year. Thanks for Liking and sharing our posts and tweets, for spreading the word about what we do, and for offering so many kind words of support. We may have moved from the old domain and site layout, but we’re still here and we aren’t slowing down. Lots more new podcasts, articles, and other surprises are on their way. See you in 2016!