Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Scottish actress Karen Gillan (L) and guests attend the Guardians of the Galaxy Vol. 3 World Premiere at the Dolby Theatre in Hollywood, California on April 27, 2023. (Photo by Rich Polk/Getty Images for Disney)