Fifty of the largest neurons of the fly brain connectome. Image credit: Tyler Sloan and Amy Sterling for FlyWire, Princeton University, (Dorkenwald et al., Nature, 2024) Written by Dan Vahaba Feb. 27, 2025 A team of researchers at the Princeton Neuroscience Institute (PNI) has been awarded a $1.2M grant from the W.M. Keck Foundation to determine how the brain’s wiring diagram gives rise to the activity of every neuron in the brain. This work builds on the recently mapped wiring diagram of the fruit fly brain, which mapped all 139,255 neurons in the fly brain, along with >50 million synaptic connections. “We're at this unique moment in time where there's been a lot of excitement over building connectomes,” said Andrew Leifer, Ph.D., one of the grant’s investigators and an associate professor of neuroscience and physics. “Mala Murthy and Sebastian Seung recently had a whole Nature issue about the fly connectome, and I come from studying the roundworm’s connectome, so we’re all really interested in how a network’s wiring, along with its genes and molecules, enables brain function.”Leifer, along with PNI’s director Mala Murthy, Ph.D., professor of neuroscience David Tank, Ph.D., and professor of neuroscience and computer science Sebastian Seung, Ph.D., will make use of the fruit fly’s charted brain map to guide the development of their new technology that aims to simultaneously measure the activity of each one of the fly’s nearly 140,000 neurons while also allowing precise control of single neurons.By activating individual brain cells while observing the entire brain, the team hopes to understand how each neuron contributes to the network as a whole. In addition to being an important technical feat, the work might also shed light on how brain cells across animals, including people, operate.“This is foundational research to understand how healthy brains work,” Leifer said. “This broader question of how brain function emerges from wiring and genes is potentially quite universal and we might expect the kind of patterns or principles we see in flies to apply to mice or primates or even humans.”###About the W. M. Keck FoundationBased in Los Angeles, the W. M. Keck Foundation was established in 1954 by the late W. M. Keck, founder of the Superior Oil Company. The Foundation’s grant making is focused primarily on pioneering efforts in the areas of medical research and science and engineering. For more information, visit www.wmkeck.org Related People Andrew Leifer Mala Murthy H. Sebastian Seung David Tank
