Brain organoids derived from human embryonic stem cells being grown in the labARTHUR CHIEN/SCIENCE PHOTO LIBRARYHuman mini-brains that contain 80 per cent of the cell types in a 40-day-old fetal brain have been created by fusing different organoids together.Were getting to the point that we are getting closer to the fetal brain, says Annie Kathuria at Johns Hopkins University in Maryland. The reason for doing this is to create organoids that are better suited for studying conditions such as autism and schizophrenia, which is hard to do in animals, she says.