Conflicts between local and global spatial frameworks dissociate neural representations of the lateral and medial entorhinal cortex.
Conflicts between local and global spatial frameworks dissociate neural representations of the lateral and medial entorhinal cortex.
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DOI：
10.1523/jneurosci.0946-13.2013
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发表时间：
2013-05-29
期刊：
影响因子：
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通讯作者：
Knierim JJ
中科院分区：
文献类型：
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作者：
Neunuebel JP;Yoganarasimha D;Rao G;Knierim JJ
空间参考框架的操作是研究海马信息编码性质和研究高阶过程（如认知协调）的常用实验工具。然而，尚不清楚海马体事件如何代表环境的局部和全局参考框架。为了解决这些问题，在自由运动的大鼠中，用多个四极阵列记录了单个单元，目标是外侧内嗅皮层（LEC）和内侧内嗅皮层（MEC）的浅层，这是海马的两个主要皮层输入。老鼠顺时针绕着一个圆形轨道跑，这个轨道被划分成不同纹理的象限（当地参考框架）。赛道以圆形环境为中心，墙壁上有明显的地标（全球参考框架）。在这里，我们展示了MEC和LEC之间的一种新的分离，即当参考帧以相等但相反的方向旋转时，全局帧控制MEC表示，局部帧控制LEC表示。考虑到海马体回路的功能解剖和CA3吸引子动力学的流行模型，可以从机制上解释之前的数据，这些数据显示CA3和CA1区域在对这种局部-全局冲突的反应中存在分离。此外，这些结果与LEC向海马体提供经验的外部感觉内容和MEC提供空间背景的模型一致，这两个模型结合在一起在海马体中形成连接代码，构成情景记忆的基础。
Manipulation of spatial reference frames is a common experimental tool to investigate the nature of hippocampal information coding and to investigate high-order processes, such as cognitive coordination. However, it is unknown how the hippocampus afferents represent the local and global reference frames of an environment. To address these issues, single units were recorded in freely moving rats with multi-tetrode arrays targeting the superficial layers of the lateral entorhinal cortex (LEC) and medial entorhinal cortex (MEC), the two primary cortical inputs to the hippocampus. Rats ran clockwise laps around a circular track partitioned into quadrants covered by different textures (the local reference frame). The track was centered in a circular environment with distinct landmarks on the walls (the global reference frame). Here we demonstrate a novel dissociation between MEC and LEC in that the global frame controlled the MEC representation and the local frame controlled the LEC representation when the reference frames were rotated in equal, but opposite, directions. Consideration of the functional anatomy of the hippocampal circuit and popular models of attractor dynamics in CA3 suggests a mechanistic explanation of previous data showing a dissociation between the CA3 and CA1 regions in their responses to this local–global conflict. Furthermore, these results are consistent with a model of the LEC providing the hippocampus with the external sensory content of an experience and the MEC providing the spatial context, which combine to form conjunctive codes in the hippocampus that form the basis of episodic memory.