In what sounds like the first act of a Syfy creature feature, scientists are growing human brain “organoids” from stem cells and raising scary ethical questions as they seek to develop these proto-brains further in their laboratories and in other organisms.
What could possibly go wrong?
Minuscule blobs of human brain tissue have come a long way in the four years since scientists in Vienna discovered how to create them from stem cells.
The most advanced of these human brain organoids — no bigger than a lentil and, until now, existing only in test tubes — pulse with the kind of electrical activity that animates actual brains. They give birth to new neurons, much like full-blown brains. And they develop the six layers of the human cortex, the region responsible for thought, speech, judgment, and other advanced cognitive functions.
Despite developing all the parts associated with a normal human brain, scientists don’t “believe” these organoids can think.
These micro quasi-brains are revolutionizing research on human brain development and diseases from Alzheimer’s to Zika, but the headlong rush to grow the most realistic, most highly developed brain organoids has thrown researchers into uncharted ethical waters. Like virtually all experts in the field, neuroscientist Hongjun Song of the University of Pennsylvania doesn’t “believe an organoid in a dish can think,” he said, “but it’s an issue we need to discuss.”
Imagine that nightmarish existence if they’re wrong. A lentil-sized brain with consciousness but without any sensory input connecting you to reality. You’d be like Keith Olbermann.
While it would seem unlikely at this point that these in a dish can think, they’re obviously not stopping there.
They’ve got big plans which include connecting the organoids to a blood supply, which presumably would allow them to grow.
They’re also looking at implanting them in rodents (again, see also Keith Olbermann).
At a neuroscience meeting, two teams of researchers will report implanting human brain organoids into the brains of lab rats and mice, raising the prospect that the organized, functional human tissue could develop further within a rodent. Separately, another lab has confirmed to STAT that it has connected human brain organoids to blood vessels, the first step toward giving them a blood supply.
That is necessary if the organoids are to grow bigger, probably the only way they can mimic fully grown brains and show how disorders such as autism, epilepsy, and schizophrenia unfold. But “vascularization” of cerebral organoids also raises such troubling ethical concerns that, previously, the lab paused its efforts to even try it.
The scientists need to develop these organoids into something closer to an actual human brain in order to study brain disorders more effectively, which raises a lot of ethical questions. It’s no mere coincidence that so many creepy GIFs from science fiction movies about brains are available. Science fiction often explores these ethical questions long before they become real concerns. The teams working on this research often have ethicists on board to keep them in check.
Rapid advances in genomics and stem cell biology are forcing researchers to regularly confront ethical quandaries that seem straight out of science fiction. The power to create organisms with cells, tissue, and even organs from different species, called a chimera, raises thorny questions: What is the moral status of a primordial human brain nourished with a rudimentary heart and circulatory system, all inside a mouse scaffold? Can it feel pain? Should it not be created in the first place?
Something tells me that despite any ethical issues, the question whether these chimeras should be created has already been superseded by the questions of who will create them and when. The genie may well be out of the bottle already.