Human mini-brains – known by those who don’t want to attract negative attention as ‘cerebral organoids' (a great name for a band) -- have been grown in Petri dishes by researchers for a number of years under the noble cause of helping people with neurological diseases and always with the stated understanding that these mini-brains were not capable of actually thinking. Oops. According to a new study just released, these human mini-brains can now produce brain waves that are indiscernible from some newborn humans. Uh-oh.
“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.”
Biologist Alysson Muotri of the University of California, San Diego, led the research and co-authored the paper published in the journal Cell Stem Cell and summarized in various scientific publications, including STAT and Nature. He is also the co-founder and part owner of Tismoo, a Brazil-based company attempting to create brain organoids from the cells of people with rare neurological disorders and then test experimental therapies on them. Muotri and his team have focused on keeping the mini-brains alive, fed and healthy for several years so that the cells can mature just as they would in a human skull.
“What we have in a dish is following the trajectory of human brain development.”
How far along the trajectory have the cerebral organoids in the dish followed? The latest batch generated several types of brain waves that were detected by electrodes, including gamma waves, alpha waves, and delta waves. Of course, it’s one thing to detect waves. It’s another to measure how close they are to human brain waves. For that, the team turned to an artificial intelligence system trained on the EEGs recorded from 39 premature infants born after 24 to 38 weeks of gestation. The AI thought the brain waves in the human mini-brains matched those in human babies at comparable stages of development. These activities were spontaneous and self-generated, just like in prenatal fetuses.
It’s a good thing they’re not being exposed to external stimuli that they can learn from … right?
You’re so naive. Last month, mini-brains were sent to the International Space Station to test how they handle microgravity. Are they being readied to be sent on long-duration space flights where they develop as they travel? Muotri and his team are getting ready to grow the mini-brains larger than the current pea size by supplying them with more nutrients and oxygen and surrounding them with human blood vessels. At some point, Muotri believes they will face the inevitable development – consciousness. He seems so certain that he’s hosting a conference in October of biologists and philosophers to discuss how to prove or disprove the presence of consciousness in a human mini-brain.
“As a scientist, I want to get closer and closer to the human brain. I want to do that because I see the good in it. I can help people with neurological conditions by giving them better treatments and better quality of life. But it’s up to us to decide where the limit is.”
How close is he? Will the meeting draw the line at a place he’s already passed? Will other countries recognize and respect these limits? We can’t even agree on when this occurs in actual human babies. Shouldn’t we figure that out first?
Or are we too late?
Consider this food for YOUR brain.