A team of researchers led by neuroscientist Alysson Muotri of the University of California, San Diego, coaxed human stem cells to form tissue from the cortex — a brain region that controls cognition and interprets sensory information. They grew hundreds of brain organoids in culture for 10 months, and tested individual cells to confirm that they expressed the same collection of genes seen in typical developing human brains1. Muotri and his colleagues continuously recorded electrical patterns, or electroencephalogram (EEG) activity, across the surface of the mini brains. By six months, the organoids were firing at a higher rate than other brain organoids previously created, which surprised the team. The EEG … Continue reading Alysson Muotri