Scientists Map Every Neuron in a Grain of Brain, Illuminating the Secrets of Sight
A groundbreaking international study led by over 150 scientists has produced the most detailed map ever of how visual information moves through the brain, uncovering more than 500 million intricate connections within a speck of mouse brain tissue and bringing the world closer to understanding how we see. Published in the journal Nature on April 9, 2025, the research combines genetic engineering, high-powered electron microscopy, and deep learning to capture not only the physical wiring of over 200,000 brain cells but also their real-time electrical activity in response to visual stimuli. The project—hailed as one of the most complex neuroscience experiments ever attempted—has generated a dataset of unprecedented size and detail: 1.6 petabytes, about the equivalent of 22 years of continuous high-definition video, all representing a single grain-sized fragment of brain.