Scientists rebuilt human brain circuits in the lab and discovered that the thalamus acts as a central organizer of cortical wiring. The findings offer new insight into how brain networks form and why they sometimes go awry.

A team of researchers in Japan has recreated key human neural circuits in a laboratory setting by using tiny, multi-region brain models known as assembloids. These structures are grown from induced pluripotent stem (iPS) cells and combine multiple brain-like regions into a single system. Using this approach, the researchers showed that the thalamus plays a vital role in shaping specialized neural circuits within the human cerebral cortex.