Saturday, July 28, 2018

Neanderthal "Mini-Brains"

Scientists Are Growing Neanderthal "Mini-Brains" in the Lab

Written by Reuben Westmaas

You know, we're really glad that after all this time, Neanderthals are finally starting to get the respect that they deserve. Modern human always used to assume that the hominids that came before were denser, dumber, and less creative than our beautiful selves (though possibly less narcissistic). But the more we've learned, the more respect we've gained for what was going on inside Neanderthal craniums. That might be why scientists are now growing miniature Neanderthal brains in the lab. You heard us right.



Alysson R. Muotri, Ph.D. / UCSD School of Medicine

The Operation Behind the Brains

If you're still hanging on to the idea of Neanderthals as primitive proto-humans who never stood a chance against our intellect, then think again. There isn't much reason to think they were less intelligent than we were — and we've already told you about how they may have invented art and medicine. Still, it makes some sense that the stereotype would hang on for so long. We've never had a real, live Neanderthal to speak to, and we've only been able to make a guess here or there about their brain function by the shape of their skulls. But now, thanks to recent advances in gene mapping and editing and a new practice of growing tiny "organoids" in the laboratory, scientists are finally able to see exactly what a Neanderthal brain is capable of.

Believe it or not, these Neanderthal mini-brains aren't the first fun-size gray matter grown in a lab. Organoids like these are only "brains" in the sense that they're tiny clusters of brain cells — they don't actually have the structure to produce any sort of thought, and they only indicate the earliest phases of brain development. Still, by targeting one of the 200 protein-carrying genes that set humans and Neanderthals apart, University of San Diego geneticist Allyson Muotri has broken new ground in the field of paleoneurology.

The gene they targeted was NOVA1, which is essential to neurodevelopment and has been linked with schizophrenia and autism in humans. First, they modified human stem cells to carry the Neanderthal version of NOVA1, then they coerced those cells into growing into the tiny brains. Although no work has been published from these types of experiments yet, the Neanderthal mini-brains clearly set themselves apart from human ones after months of development.


Alysson R. Muotri, Ph.D. / UCSD School of Medicine

Popcorn Brain

For now, the researchers aren't willing to say what their discoveries mean in terms of how Neanderthal brains worked. And that makes sense, seeing as these organoids aren't full organs, though over time we'll be able to learn a lot more about what makes them tick. But even from a glance, the Neanderthal brains are much different from human ones. Whereas unaltered brain organoids from neurotypical people grew as pea-sized spheres, the ones with the Neanderthal sequence developed a bumpy, popcorn-like shape, grew fewer synaptic connections, and developed what appeared to be an abnormal neuronal network. Muotri noted that in some ways, this network resembled the neuronal development of brains with autism, but emphasized that the significance of that resemblance is completely unknown.

This isn't the end of Muotri's plans for these organoids. In fact, his schemes are getting even more Bond-villain-esque. Now that he's got a collection of human and Neanderthal brain organoids, he's attempting to wire the human ones to small robots that resemble crabs in hopes that the mini-brains will learn to pilot them. The next step? Pit the human-crab-robots against Neanderthal-crab-robots and see who comes out on top. (We're not even making this up.) As for what comes after that, well, we're just hoping it doesn't involve sharks with laser beams.

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