A new discovery by neuroscientists at Brown University’s Carney Institute for Brain Science challenges long-held beliefs in neurobiology about how neurons extend axons to reach their targets.

Published in Proceedings of the National Academy of Sciences, the findings provide what the authors call a “genetic atlas” of neuronal development, as well as a potential step forward for understanding how to repair broken neural connections in conditions such as stroke and spinal cord injury.

“We discovered that during development, neurons turn on and off entire groups of genes that allow their axons to grow through different sections of their path,” said study author Alexander Jaworski, an associate professor of brain science at the Carney Institute. “That’s surprising.”