美国加州大学Michael M. Yartsev研究组近日取得一项新成果。经过不懈努力，他们研究出自由飞行蝙蝠海马的重放与再现动力学。这一研究成果发表在2025年7月9日出版的国际学术期刊《自然》上。

该课题组无线记录了大量细胞的神经活动和海马体的局部场电位（LFP），这些自由飞行的蝙蝠从事自由、自发的觅食行为。在休息期间，该课题组确定了与锐波波纹（SWR）相一致的多个飞行轨迹的时间压缩正向和反向重放。然而，重播主要发生在距离重播行为在空间和时间上都较远的位置，其速度随轨迹长度而变化，挑战了现有的重播机制模型。在飞行过程中，神经系统表现出快速的代表性扫描，其中解码的位置循环地移动到蝙蝠的位置之前。

与啮齿类动物的报道相反，扫描发生在没有θ波振荡的情况下，而是与一个突出的运动行为节奏——蝙蝠的振翅周期相锁定。这表明与行为相关的感觉运动节律可以以高度结构化的方式与海马体整体动力学相互作用。综上所述，他们的发现挑战了哺乳动物海马体中现有的整体动力学模型，并强调了在动物行为学相关条件下进行比较研究对于阐明脑功能的重要性。

据悉，导航和记忆的认知功能依赖于海马体中神经系统的涌现特性，如活动重放和θ序列。然而，这些现象是否以及如何在具有不同导航需求和神经生理特性的物种中普遍存在仍不清楚。

附：英文原文

Title: Replay and representation dynamics in the hippocampus of freely flying bats

Author: Forli, Angelo, Fan, Wudi, Qi, Kevin K., Yartsev, Michael M.

Issue&Volume: 2025-07-09

Abstract: Cognitive functions for navigation and memory rely on emergent properties of neural ensembles in the hippocampus, such as activity replay1–5 and theta sequences6–9. Yet, whether and how these phenomena generalize across species with distinct navigational demands and neurophysiological properties remain unclear. Here, we wirelessly recorded neural activity from large populations of cells and local field potentials (LFPs) from the hippocampus of freely flying bats engaged in free, spontaneous foraging behavior. During rest, we identified time-compressed forward and reverse replay of multiple flight trajectories coinciding with sharp-wave ripples (SWRs). Yet, replays occurred predominantly at locations that were both spatially and temporally distant from the replayed behavior, and their speed scaled with trajectory length, challenging existing models of replay mechanisms. During flight, neural ensembles exhibited fast representational sweeps, where the decoded location cyclically moved ahead of the bat’s position. In contrast to reports in rodents, sweeps occurred in the absence of theta oscillations and were instead phase-locked to a prominent motor behavioral rhythm - the bat’s wingbeat cycle. This suggests that behaviorally-relevant sensorimotor rhythms can interact with hippocampal ensemble dynamics in a highly structured manner. Combined, our findings challenge existing models of ensemble dynamics in the mammalian hippocampus and highlight the importance of comparative studies under ethologically relevant conditions for elucidating brain function.

DOI: 10.1038/s41586-025-09341-z

Source: https://www.nature.com/articles/s41586-025-09341-z