If 2012 was the year neuroscience exploded into pop culture, 2013 was the year it stepped into the halls of power.
The Obama administration’s $100-million BRAIN Initiative stirred up furious debate, as proponents cheered to see so much funding and press attention thrown at large-scale efforts to map the human brain, while opponents claimed that the whole thing might be a gigantic waste of valuable resources. Meanwhile, across the Atlantic, the European Union’s Human Brain Project sparked similar disputes – disputes that continue even as unexpected breakthroughs have begun to surface.
It’s also been a year of explosive growth here at The Connectome. I’ve been spending less time posting on this blog because (gratuitous brag alert!) I’m now regularly blogging for national press outlets like Scientific American, The Huffington Post, Forbes and Discover Magazine. But when I do post here, I make sure to leverage every connection in my address book to bring you guys bigger, cooler, more exciting content – like podcast interviews with researchers like Oliver Sacks, David Eagleman and Sebastian Seung. On other fronts, my TEDx talk finally made it onto YouTube, you guys have been showing love for my webseries, “DEBUNKALYPSE,” and The Connectome’s Facebook, Google Plus and Twitter feeds each broke 1,000 followers this year.
None of this could’ve happened without you guys. I owe this all to you. You’re awesome. I mean it. And lots more cool stuff is on the horizon, I promise.
But enough about how amazing The Connectome is. That’s not why you’re here.
And so, without further fanfare, here – in countdown order – are the five most thrilling neuroscience discoveries of 2013!
5. The Emergence of Individuality in Clones
If you’ve ever raised a litter of newborn puppies or kittens, you’ve seen that each baby displays its own personality right from the start. Some are feisty and adventurous, some hog all the milk, some hide close to mom, some bully their siblings mercilessly, and so on. Years of studies have found that this is even true of genetically identical animal clones – but it wasn’t until 2013 that Gerd Kempermann, a professor of genomics at the Center for Regenerative Therapies (CRTD) in Dresden, Germany, scoped out exactly how these differences in experience shape the unique development of each individual’s brain. Kempermann and his team cloned a group of genetically identical mice and set them loose in a large enclosure with lots of places to play. Within just a few months, the mouse clones that had explored the most actively had sprouted new nerve cells throughout their brains – especially in the hippocampus, a region that’s crucial for memory – while the less-adventurous clones showed less brain development. Although this research doesn’t tell us why some mouse clones were more adventurous in the first place, it’s still a clear demonstration that individual experiences sculpt individual brains, right from the earliest months of life – even if those brains are genetically identical.
4. “Two Brains in One Cortex”
Your cerebral cortex – the outermost “rind” or “bark” of that cauliflowery mass that makes up most of your brain – isn’t just a single structure. All across your brain, the cortex is divided into stacked layers of neurons, many of them overlapping like the patches of a quilt. Each layer plays its own part in processing information; and since the early twentieth century, most neuroscientists have taught that these layers work as a strict hierarchy: That each layer does its part, then passes its results on to the next layer, all nice and orderly-like. But in 2013, Columbia University neuroscientist Randy Bruno showed that cortical layers 4 and 5 both receive “copies” of the same exact information, and perform their processing simultaneously. The discovery led Bruno to declare, “It’s almost as if you have two brains built into one cortex.” The exact implications of this revised cortical hierarchy aren’t quite clear yet – but it’s another humbling reminder that our understanding of brain wiring is still at a very primitive stage.
3. “Mini-Computers” Hidden in Nerve Cells
For more than 100 years of brain research, scientists thought that dendrites – those branch-like projections that connect one neuron to others – were just passive receivers of incoming information. But in 2013, researchers at the University of North Carolina at Chapel Hill demonstrated that dendrites do a lot more than just passively relay signals – they also perform their own layer of active processing, hinting that the brain’s total computing power may be many times greater than anyone expected. This discovery is so new that no one’s had much time to figure out what, exactly, all this additional processing power changes about our understanding of the brain; or how we’ll have to revise our models of brain function to incorporate it. But mark my words – this is gonna turn out to be a major paradigm shifter over the next few years.
2. Crowdsourced Connectomics
When researchers first started talking seriously about human connectomics – the science of constructing cellular-level wiring diagrams for entire regions of the human brain – back in 2005, supporters of the idea were all but laughed out of the building. We had nowhere near enough computing power, opponents claimed, to even attempt to map the human brain’s 84 billion (-ish) neurons and 100 trillion (-ish) interconnections – and even if we did, we’d still need humans to double-check every synapse the computers tried to map. Even today, the science of human connectomics has loads of vocal critics. But in 2013, a collaborative effort by researchers at MIT, along with another team at Germany’s Max-Planck Institute for Medical Research, used an innovative combination of computerized rendering and human tracing to map the precise shapes and points of contact between all 950 neurons in a patch of mouse retina – and they did it in 1/100th of the time, and at a fraction of the cost, that naysayers predicted. It’s a small step in the grand scheme of connectomics, but it’s a proof-of-concept for a cheap, efficient technique that can be applied throughout an entire brain – and a hint that the dream of a complete human connectome isn’t necessarily out of reach in our own lifetimes.
1. The Human Brain-to-Brain Interface
Back in 2012, researchers at Harvard found that if they stuck electrodes into certain points in the brains of two rats, they could enable the first rat to control the physical movement of the second one using only the power of its thoughts. Human-to-rat interfaces soon followed – but it wasn’t until 2013 that University of Washington scientists Rajesh Rao and Andrea Stocco created the first human-to-human wireless brain-to-brain interface. Sitting on one side of campus, Rao thought, “tap the spacebar,” and at the other end of campus, Stocco’s hand tapped his spacebar involuntarily. It’s a simple interface, but the implications aren’t hard to see: Movement impulses – and someday, perhaps even thoughts and memories – can be beamed directly from one human brain to another.
And those are The Connectome’s picks for the most fascinating, transformative, implication-riddled neuroscience breakthroughs of 2013. What about you – which of this year’s discoveries do you think made the biggest waves? Which ones are poised to change the world? Which ones did I miss? Jump into the comments and tell us all what’s up!