Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 7034 Trondheim, Norway.
Division of Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, 97074 Würzburg, Germany.
Proc Natl Acad Sci U S A. 2024 Feb 20;121(8):e2320764121. doi: 10.1073/pnas.2320764121. Epub 2024 Feb 12.
Many animal species rely on the Earth's magnetic field during navigation, but where in the brain magnetic information is processed is still unknown. To unravel this, we manipulated the natural magnetic field at the nest entrance of desert ants and investigated how this affects relevant brain regions during early compass calibration. We found that manipulating the Earth's magnetic field has profound effects on neuronal plasticity in two sensory integration centers. Magnetic field manipulations interfere with a typical look-back behavior during learning walks of naive ants. Most importantly, structural analyses in the ants' neuronal compass (central complex) and memory centers (mushroom bodies) demonstrate that magnetic information affects neuronal plasticity during early visual learning. This suggests that magnetic information does not only serve as a compass cue for navigation but also as a global reference system crucial for spatial memory formation. We propose a neural circuit for integration of magnetic information into visual guidance networks in the ant brain. Taken together, our results provide an insight into the neural substrate for magnetic navigation in insects.
许多动物物种在导航时依赖于地球磁场，但磁场在大脑中的处理位置仍不清楚。为了解开这个谜团，我们在沙漠蚂蚁的巢穴入口处操纵自然磁场，并研究了这如何在早期罗盘校准过程中影响相关的大脑区域。我们发现，操纵地球磁场对两个感觉整合中心的神经元可塑性产生了深远的影响。磁场操纵会干扰在学习过程中蚂蚁典型的“回望”行为。最重要的是，对蚂蚁神经元罗盘（中央复合结构）和记忆中心（蘑菇体）的结构分析表明，磁场信息会影响早期视觉学习过程中的神经元可塑性。这表明，磁场信息不仅可以作为导航的罗盘线索，还可以作为对空间记忆形成至关重要的全局参考系统。我们提出了一个神经回路，用于将磁场信息整合到蚂蚁大脑中的视觉引导网络中。总之，我们的研究结果为昆虫的磁场导航的神经基础提供了新的见解。
