This handout image obtained from the press service of Springer Nature Publishing Group on August 19, 2026 shows a view taken in March 2023 in the Arlotta Lab, Department of Stem Cell and Regenerative Biology of Harvard University of brain organoids, human brain cells grown in a lab by Harvard researchers. 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 on August 19, 2026. These tiny clumps called organoids are grown from stem cells by scientists around the world in the hopes of uncovering the mysteries of our brain -- and to test new medicine without having to use animals such as mice. (Photo by Noelia ANTON-BOLANOS and Irene FARAVELLI / Springer Nature / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/ Press service of Springer Nature Publishing Group / Noelia ANTON-BOLANOS/ Irene FARAVELLI/HANDOUT/ - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVE / TO GO WITH AFP STORY BY Daniel LAWLER