How to build a human brain

Some steps for growing mini versions of human organs are easier than others

organoid brain

BRAIN-MAKING 101  As blobs of two types of brainlike tissue fuse, interneurons (green) migrate from the left clump to the right, linking with neurons (not stained) in the right blob. On both sides, neural support cells called glia appear in purple.

Paşca Lab/Stanford Univ.

In a white lab coat and blue latex gloves, Neda Vishlaghi peers through a light microscope at six milky-white blobs.