Lab Grown Mini-Brains Raise Some Ethical Questions

Huh.

From the journal Science:

Exclusive: Neanderthal ‘minibrains’ grown in dish

Until now, researchers wanting to understand the Neanderthal brain and how it differed from our own had to study a void. The best insights into the neurology of our mysterious, extinct relatives came from analyzing the shape and volume of the spaces inside their fossilized skulls.

But a recent marriage of three hot fields—ancient DNA, the genome editor CRISPR, and "organoids" built from stem cells—offers a provocative, if very preliminary, new option. At least two research teams are engineering stem cells to include Neanderthal genes and growing them into "minibrains" that reflect the influence of that ancient DNA.

None of this work has been published, but Alysson Muotri, a geneticist at the University of California, San Diego (UCSD) School of Medicine, described his group's Neanderthal organoids for the first time this month at a UCSD conference called Imagination and Human Evolution. His team has coaxed stem cells endowed with Neanderthal DNA into pea-size masses that mimic the cortex, the outer layer of real brains. Compared with cortical minibrains made with typical human cells, the Neanderthal organoids have a different shape and differences in their neuronal networks, including some that may have influenced the species's ability to socialize. "We're trying to recreate Neanderthal minds," Muotri says.

“I'm a little envious,” says Todd Preuss, a neuroanatomist at Emory University's Yerkes National Primate Research Center in Atlanta who is retiring just as this approach to studying brain evolution takes hold. “It's still a long haul to get from organoids to real brains, but if the technique can be developed enough to give us more information about normal tissue structure, then you've got something that's probably very useful.”

Svante Pääbo, director of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, expects the work to draw skepticism because it's so difficult to figure out which genetic differences are “functionally relevant,” and the organoids only represent the early stage of brain development. “Organoids are far from being able to tell us how adult brains function,” says Pääbo, who led the team that deciphered the Neanderthal genome by rescuing DNA from their bones. His group has also started to make organoids with Neanderthal brain genes, but he stresses that the technique can introduce unintended mutations. “There are lots of control experiments to do, and then I'm quite hopeful we'll overcome those doubts,” says Pääbo, who plans to compare Neanderthal brain organoids to those made from chimpanzee or modern human cells....MORE

And via Science Daily, it works for humans too!:

Building a better brain-in-a-dish, faster and cheaper

Date:

September 6, 2018

Source:

University of California - San Diego

Summary:

Researchers report on the development of a new protocol for creating human cortical organoids -- mini-brains derived directly from primary cells that can be used to better explore and understand the real thing.

Writing in the current online issue of the journal Stem Cells and Development, researchers at University of California San Diego School of Medicine describe development of a rapid, cost-effective method to create human cortical organoids directly from primary cells.

Experimental studies of developing human brain function are limited. Research involving live embryonic subjects is constrained by ethical concerns and the fragile nature of the brain itself. Animal models only partially mimic or recapitulate human biology and cognitive function. Single cell studies do not capture the complexity of neural networks.

In recent years, the development of in vitro human organoids -- three-dimensional, miniaturized, simplified versions of an organ produced from reprogrammed stem cells -- have allowed scientists to study biological functions, diseases and treatments more realistically and in greater detail.

"And that includes the brain," said Alysson R. Muotri, PhD, professor in the UC San Diego School of Medicine departments of Pediatrics and Cellular and Molecular Medicine, director of the UC San Diego Stem Cell Program and a member of the Sanford Consortium for Regenerative Medicine. "Cerebral organoids can form a variety of brain regions. They exhibit neurons that are functional and capable of electrical excitation. They resemble human cortical development at the gene expression levels."...MORE