Story Brief

Peppercorn-sized clumps of human brain cells grown in a lab for a record seven years aged similarly to those inside our heads, suggesting they "recorded the passage of time," scientists said Wednesday. These tiny clumps, called organoids, are grown from stem cells by scientists around the world in the hope of uncovering the mysteries of our brains—and to test new medicines without having to use animals such as mice.

AI summaries can be wrong sometimes—always verify important details using the source article.