A small bundle of human nerve cells are being cultured in a petri dish. The cells divide. They differentiate into cell types found in the brain. The cell network grows dense and develops brain-like structures—layers and folds. The cells begin to signal. The brain cell cluster has been derived from skin cells harvested from science writer Philip Ball’s shoulder.
The scientists who created Ball’s skin-turned-brain “organoid” study brain development and want to understand the basis of neurodegeneration. But what exactly goes on inside these cell aggregates, and could we reach a point at which they are more “brain” than “brain-like”?