Inertial and multisensory influences on entorhinal grid cells

项目摘要 动物导航的基础上自我运动线索和外部参考，这有助于纠正错误 在路径整合中积累。内侧内嗅皮层（MEC）中的细胞编码方向，速度和方向。 位置，并且它们的输出可以表示路径集成的神经基础。前庭系统提供 角运动和线性运动的信息，以及病变研究表明， 集成导航。是否以及如何做到这一点是一个谜。近年来，虚拟- 虚拟现实（VR）在探索导航电路方面已经成为时尚。值得注意的是，二维（2D）网格 头部固定的啮齿类动物体验VR时的性能会受到影响。这里要检验的假设是， 这是因为惯性（前庭）信号与运动和视觉线索相冲突， 与现实世界的导航形成对比，在现实世界中，来自前庭、视觉和其他感官的一致的多感官线索 所有的形式都汇聚在一起，产生了空间运动的感觉。在VR中，只有视觉和 存在本体感受线索，而前庭线索不发出运动信号。为了验证惯性的假设 运动线索是必要的空间编码在MEC中，我们已经建立了一个独一无二的VR设备（鼠标 头部固定并在安装在运动平台顶部的空气膨胀的泡沫聚苯乙烯球上运动）， 其可以提供惯性加速度。创造VR环境的视觉刺激以及 平台的移动都由鼠标的移动和所产生的球旋转来控制。 我们将在导航过程中监测网格细胞的活动，而旋转和/或平移多感官线索是 独立和系统地操纵。我们的发现可能会彻底改变我们对 MEC中空间代码的性质和属性，通过将不同的专业知识和两个分离的 （导航/MEC/海马和前庭/多感觉）社区。

PROJECT SUMMARY Animals navigate based on self-motion cues and external references, which serve to correct errors accumulated in path integration. Cells in the medial entorhinal cortex (MEC) encode direction, speed and position, and their output could represent the neural basis for path integration. The vestibular system provides information for angular and linear motion, and lesion studies have suggested that it may be important for path integration-based navigation. Whether and how this is done represents a mystery. In recent years, virtual- reality (VR) has become fashionable in exploring the navigation circuit. Remarkably, two-dimensional (2D) grid properties are compromised in head-fixed rodents experiencing VR. The hypothesis to be tested here is that this occurs because inertial (vestibular) signals are in conflict with locomotion and visual cues – which contrasts with real-world navigation where congruent multisensory cues from vestibular, visual and other modalities all converge to give rise to the sense of motion through space. In VR, only the visual and proprioceptive cues are present, while vestibular cues signal no motion. To test the hypothesis that inertial motion cues are necessary for space coding in the MEC, we have built a one-of-a-kind VR apparatus (mouse is head-fixed and locomoting on an air cushioned Styrofoam ball) that is mounted on top of a motion platform, which can provide inertial accelerations. The visual stimulus creating the VR environment as well as the movement of the platform are both controlled by the locomotion of the mouse and the resulting ball rotation. We will monitor grid cell activity during navigation, while rotation and/or translation multisensory cues are independently and systematically manipulated. Our findings could revolutionize our understanding of the nature and properties of the spatial code in MEC by bridging together diverse expertise and two segregated (navigation/MEC/hippocampus and vestibular/multisensory) communities.