In an important discovery published on April 10, 2025, researchers have created the most detailed brain activity map ever. Scientists at Baylor College of Medicine carried out an experiment using a specially engineered mouse. As it watched various video clips—including scenes from the movie The Matrix—the mouse’s neurons would glow whenever active, enabling researchers to observe brain activity directly. To investigate further, the team took a tiny brain sample, only as big as a poppy seed. Advanced imaging techniques revealed more than 84,000 neurons and about 500 million connections between them, demonstrating the brain’s complexity. Over 150 scientists from leading institutions such as the Allen Institute and Princeton University collaborated on this project, sharing the data online for researchers worldwide. Using powerful electron microscopes and artificial intelligence, the scientists built a 3D digital model resembling tangled spaghetti, clearly illustrating how signals travel through the brain. This breakthrough could significantly advance studies of brain disorders like Alzheimer’s and autism. Princeton neuroscientist Sebastian Seung believes their new tools could even help identify abnormal brain patterns.