Alysson Muotri and his team have been toiling away in the lab for the last year and a half or so, obsessing over bland-looking, pea-sized lumps of cells. Despite their unassuming appearance, lumps like these have taken neuroscience by storm. They’re lab-grown “brains.” Scientists call them brain organoids, and they offer rudimentary 3-D models of the brain’s cortex — the outer layer where complex functions like memory, language, and likely self-awareness, play out — created in petri dishes from stem cells.
Muotri and his team aren’t the first to develop brain organoids. The models, sometimes called cerebral organoids, have been around since about 2013. But the University of California, San Diego neuroscientist’s lab and collaborators have been behind several innovative uses of them in recent years. In 2016, Muotri helped author research published in Nature that utilized brain organoids to show how Zika can cause birth defects. He’s also incorporated them into his work on autism. And earlier this year, he reported preliminary results from using the gene-editing tool CRISPR to create Neanderthalized variations. He and his team swapped in the Neanderthal version of a gene we modern humans have called NOVA1. It’s a so-called master regulator gene that can influence the expression of hundreds of others. And CRISPR-ing the Neanderthal equivalent into the human stem cells that evolve into organoids resulted in brain structure that mirrored some of the differences seen in people with autism.
As if that last bit weren’t crazy enough, recently, his group has been gunning to push brain organoids past their current state of simplicity — by hooking them up to a robot that allows the 3-D models to interact with the world around them.
