From the “What Could Possibly Go Wrong” Department, located right next door to the “What Were They Thinking” Department, comes word from the journal Science that researchers at the University of California San Diego School of Medicine have created Neanderthal mini-brains that mimic some of the functions of real Neanderthal brains. Why? Let’s start at the “What Were They Thinking” Department and find out.
"It's fascinating to see that a single base-pair alteration in human DNA can change how the brain is wired. We don't know exactly how and when in our evolutionary history that change occurred. But it seems to be significant, and could help explain some of our modern capabilities in social behavior, language, adaptation, creativity and use of technology."
Alysson R. Muotri, PhD, senior author of the study and director of the UC San Diego Stem Cell Program, describes in the press release his curiosity about human brain evolution and why it’s so different than Neanderthal and Denisovan brains – our closest relatives on the evolutionary path. Lacking actual DNA from either but possessing the complete genome of the Neanderthal species, sequenced in 2013 from a Neanderthal finger bone, Muotri decided to create his own using human stem cells and CRISPR-Cas9 gene editing. Since human, Neanderthal and Denisovan brains are similar, Muotri looked for genes that didn’t get passed on to humans by evolution and settled on the NOVA1 – a master gene regulator that influences many other genes during early Neanderthal brain development. That sounds like a good choice. Let’s ask the people in the “What Could Possibly Go Wrong” Department if they agree.
“The researchers used CRISPR gene editing to engineer modern human stem cells with the Neanderthal-like mutation in NOVA1. Then they coaxed the stem cells into forming brain cells and ultimately Neanderthal-ized brain organoids.”
So, they edited human stem cells using the map of NOVA1, then directed them to grow into Neanderthal brain cells and finally into Neanderthal brain organoids or mini-brains.
“If you’d asked me five years ago whether we could get organoids to generate sophisticated brain waves, I would have said no. But what we got is unprecedented. No one has ever seen this level of complexity in cerebral organoids, which is why we were so surprised.”
That comment was made in 2019 by the same Alysson Muotri after he grew human mini-brains which showed brain waves that were indiscernible from some newborn humans. This is obviously a possibility with the Neanderthal mini-brains. His team found obvious differences between them and the human mini-brains – they had a different shape, possibly because their cells and synapses between neurons formed differently. In fact, the Neanderthal mini-brains showed higher levels of electrical impulses earlier than the human mini-brains, although they didn’t synchronize into networks. Yet.
“According to Muotri, the neural network changes in Neanderthal-ized brain organoids parallel the way newborn non-human primates acquire new abilities more rapidly than human newborns.”
Is Muotri on the path to creating full-sized Neanderthal brains … and full-sized Neanderthals?
“This study focused on only one gene that differed between modern humans and our extinct relatives. Next we want to take a look at the other 60 genes, and what happens when each, or a combination of two or more, are altered.”
Don’t let the door hit you on the rear as you run screaming out of the “What Could Possibly Go Wrong” Department.