Fiete Ila R, Burak Yoram, Brookings Ted
Kavli Institute for Theoretical Physics and Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
J Neurosci. 2008 Jul 2;28(27):6858-71. doi: 10.1523/JNEUROSCI.5684-07.2008.
We characterize the relationship between the simultaneously recorded quantities of rodent grid cell firing and the position of the rat. The formalization reveals various properties of grid cell activity when considered as a neural code for representing and updating estimates of the rat's location. We show that, although the spatially periodic response of grid cells appears wasteful, the code is fully combinatorial in capacity. The resulting range for unambiguous position representation is vastly greater than the approximately 1-10 m periods of individual lattices, allowing for unique high-resolution position specification over the behavioral foraging ranges of rats, with excess capacity that could be used for error correction. Next, we show that the merits of the grid cell code for position representation extend well beyond capacity and include arithmetic properties that facilitate position updating. We conclude by considering the numerous implications, for downstream readouts and experimental tests, of the properties of the grid cell code.
我们描述了同时记录的啮齿动物网格细胞放电量与大鼠位置之间的关系。这种形式化揭示了网格细胞活动作为一种用于表示和更新大鼠位置估计的神经编码时的各种特性。我们表明，尽管网格细胞的空间周期性反应看似浪费，但该编码在容量上是完全组合式的。由此产生的明确位置表示范围远远大于单个晶格约1 - 10米的周期，能够在大鼠行为觅食范围内实现独特的高分辨率位置指定，并且具有可用于纠错的多余容量。接下来，我们表明网格细胞编码用于位置表示的优点远不止于容量，还包括有助于位置更新的算术特性。我们通过考虑网格细胞编码特性对下游读数和实验测试的众多影响来得出结论。
