Inspired by recent biological experiments, we simulate animals moving in different environments (open space, spiral mazes and on a treadmill) to test the performances of a simple model of the retrosplenial cortex (RSC) acting as a path integration (PI) and as a categorization mechanism. The connection between the hippocampus, RSC and the entorhinal cortex is revealed through a novel perspective. We suppose that the path integration is performed by the information coming from RSC. Grid cells in the entorhinal cortex then can be built as the result of a modulo projection of RSC activity. In our model, PI is performed by a 1D field of neurons acting as a simple low-pass filter of head direction (HD) cells modulated by the linear velocity of the animal. Our paper focuses on the constraints on the HD cells shape for a good approximation of PI. Recording of neurons on our 1D PI field shows these neurons would not be intuitively interpreted as performing PI. Using inputs coming from a narrow neighbouring projection of our PI field creates place cell-like activities in the RSC when the mouse runs on the treadmill. This can be the result of local self-organizing maps representing blobs of neurons in the RSC (e.g. cortical columns). Other simulations show that accessing the whole PI field would induce place cells whatever the environment is. Since this property is not observed, we conclude that the categorization neurons in the RSC should have access to only a small fraction of the PI field.

中文翻译：

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脊髓后皮质中路径整合和空间背景表示的模型。

受近期生物学实验的启发，我们模拟了在不同环境（开放空间，螺旋迷宫和跑步机）中移动的动物，以测试简单的脾后皮质（RSC）模型的性能，该模型充当路径整合（PI）和分类机制。通过新颖的观点揭示了海马，RSC和内嗅皮层之间的联系。我们假设路径集成是由来自RSC的信息执行的。然后，作为RSC活性的模投影的结果，可以建立内嗅皮层中的网格细胞。在我们的模型中，PI是由一维神经元场执行的，该一维神经元充当由动物的线速度调制的头部方向（HD）细胞的简单低通滤波器。我们的论文集中在高清单元格形状的约束上，以很好地逼近PI。在我们的一维PI字段上记录神经元表明，这些神经元不会被直观地解释为执行PI。当鼠标在跑步机上运行时，使用来自我们PI字段的狭窄相邻投影的输入会在RSC中创建类似单元格的活动。这可能是代表RSC中神经元斑点（例如皮质柱）的局部自组织图的结果。其他模拟表明，无论环境如何，访问整个PI字段都将诱导放置细胞。由于未观察到此属性，因此我们得出结论，RSC中的分类神经元应该只能访问PI字段的一小部分。当鼠标在跑步机上运行时，使用来自我们PI字段的狭窄相邻投影的输入会在RSC中创建类似单元格的活动。这可能是代表RSC中神经元斑点（例如皮质柱）的局部自组织图的结果。其他模拟表明，无论环境如何，访问整个PI字段都将诱导放置细胞。由于未观察到此属性，因此我们得出结论，RSC中的分类神经元应该只能访问PI字段的一小部分。当鼠标在跑步机上运行时，使用来自我们PI字段的狭窄相邻投影的输入会在RSC中创建类似单元格的活动。这可能是代表RSC中神经元斑点（例如皮质柱）的局部自组织图的结果。其他模拟表明，无论环境如何，访问整个PI字段都将诱导放置细胞。由于未观察到此属性，因此我们得出结论，RSC中的分类神经元应该只能访问PI字段的一小部分。