Department of Brain Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
Neuron. 2023 Jun 21;111(12):1858-1875. doi: 10.1016/j.neuron.2023.03.027. Epub 2023 Apr 11.
The symmetric, lattice-like spatial pattern of grid-cell activity is thought to provide a neuronal global metric for space. This view is compatible with grid cells recorded in empty boxes but inconsistent with data from more naturalistic settings. We review evidence arguing against the global-metric notion, including the distortion and disintegration of the grid pattern in complex and three-dimensional environments. We argue that deviations from lattice symmetry are key for understanding grid-cell function. We propose three possible functions for grid cells, which treat real-world grid distortions as a feature rather than a bug. First, grid cells may constitute a local metric for proximal space rather than a global metric for all space. Second, grid cells could form a metric for subjective action-relevant space rather than physical space. Third, distortions may represent salient locations. Finally, we discuss mechanisms that can underlie these functions. These ideas may transform our thinking about grid cells.
网格细胞活动的对称、晶格状空间模式被认为为空间提供了一种神经元全局度量。这种观点与在空盒子中记录的网格细胞是一致的，但与更自然环境下的数据不一致。我们回顾了反对全局度量概念的证据，包括在复杂和三维环境中网格模式的扭曲和瓦解。我们认为，偏离晶格对称性是理解网格细胞功能的关键。我们提出了网格细胞的三种可能功能，它们将真实世界的网格扭曲视为一种特征，而不是一种缺陷。首先，网格细胞可能构成近端空间的局部度量，而不是所有空间的全局度量。其次，网格细胞可以形成与主观动作相关的空间的度量，而不是物理空间。第三，扭曲可能代表显著位置。最后，我们讨论了可以支持这些功能的机制。这些想法可能会改变我们对网格细胞的思考方式。
