Head-direction cells as a neural compass in bats navigating outdoors on a remote oceanic island

Animals and humans rely on their navigation skills to survive. However, spatial neurons in the brain's "navigation circuit" had not previously been studied under real-world conditions. We conducted an electrophysiological study of spatial neurons in the wild: We recorded head-direction cells from the presubiculum of bats flying unconstrained and navigating outdoors on a remote oceanic island. These neurons represented the bats' orientation stably across the island's entire geographical scale and irrespective of the dynamics of the Moon and the Milky Way. The directional tuning stabilized over several nights from the first exploration of the island. These results imply that head-direction cells can serve as a learned, reliable neural compass for real-world navigation-highlighting the power of taking neuroscience out into the wild.