“In a darkened room in a laboratory in London, a group of students and researchers watch a clump of human brain cells settle into their new home: a living mouse brain. On a computer monitor next to a microscope, the human cells light up in flashes of simultaneous activity. Over time, the cells sprout new connections a few centimetres long, and form networks with each other. It’s captivating viewing for his students, says Vincenzo De Paola, who runs the lab at Imperial College London. ‘It’s all they want to do. I can’t tear them away,’ he says.
They have front-row seats to an unusual show. De Paola’s group is one of just a handful of labs able to study human neural cells at work in a live, developing brain — a system that is otherwise largely off limits for both ethical and technical reasons. ‘We cannot study these processes as they unfold in a fetal human brain,’ he says. ‘Instead, we wanted to watch human cortical neurons mature and form active networks in a live animal.’”
More on Hybrid brains: the ethics of transplanting human neurons into animals via Nature.