研究人员在印度洋一座面积约七英亩的无人岛上，对6只埃及果蝠进行了首次野外神经导航实验。研究团队在蝙蝠大脑中植入微米级电极，连续两个实验季（2023年至2024年）记录了301次飞行数据。结果显示，蝙蝠的“内部指南针”并未依赖地磁或星空，而是通过岛屿海岸线、帐篷和栖息点等地标来校准方向感。这一发现验证了在大型真实环境中，头向细胞会稳定指向固定方向，支持“全球罗盘”假说。
在实验初期的前几晚，蝙蝠的头向细胞仅粗略对应南、北、东、西等方向；到第5或第6晚，这些细胞已稳定到精确方向，并且不随蝙蝠在岛上的位置变化而重置。研究表明，尽管蝙蝠无法从岛的一端看到另一端，其大脑仍能将局部空间拼接成整体地图。此前所有相关研究几乎都在狭小封闭空间完成，而这次野外实验首次证明，实验室结论在自然尺度环境中同样成立。
该研究建立在此前2016年建成的200米隧道实验基础之上，但进一步扩展到了完全开放环境。后续未发表数据还显示，在野外条件下，导航相关细胞编码的信息量显著增加，例如位置细胞不仅记录位置，还反映飞行速度。研究人员认为，这种真实环境研究为理解哺乳动物（乃至人类）方向感提供了关键路径，也凸显了在神经科学中引入复杂自然场景的必要性。
Researchers conducted the first wild navigation experiments by studying six Egyptian fruit bats on a remote seven-acre island in the Indian Ocean. Micrometer-scale electrodes implanted in the bats’ brains recorded neural activity across two field seasons from 2023 to 2024, yielding data from 301 flights. The results showed that the bats’ “internal compass” was not anchored to Earth’s magnetic field or celestial cues, but instead relied on landmarks such as coastlines, tents, and perches, supporting the idea that spatial maps are built from environmental features.
During the first few nights, head direction cells fired only roughly for cardinal directions, but by nights five or six they stabilized to precise orientations that remained consistent regardless of where the bats were on the island. Although the bats could not see the entire island at once, their brains integrated local views into a unified global map. This behavior supports the global compass hypothesis, demonstrating that head direction cells maintain fixed directional tuning even in large, natural environments, extending conclusions previously drawn only from small laboratory spaces.
The study builds on earlier work using a 200-meter tunnel constructed in 2016, but goes further by embracing a fully open setting. Unpublished follow-up results indicate that navigation-related cells encode more information in the wild, such as place cells also reflecting flight speed. Researchers argue that these findings highlight the importance of studying brains in complex real-world conditions and offer a crucial step toward understanding mammalian, and potentially human, sense of direction.