Place cell discharge is extremely variable during individual passes of the rat through the firing field
Place cell discharge is extremely variable during individual passes of the rat through the firing field
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DOI：
10.1073/pnas.95.6.3182
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发表时间：
1998-03-17
影响因子：
11.1
通讯作者：
Muller, RU
中科院分区：
文献类型：
--
作者：
Fenton, AA;Muller, RU
大鼠海马体存储空间地图这一观点是基于“位置细胞”的存在，这些细胞呈现出“位置特异性”的放电现象。位置细胞的放电以极高的精度局限于环境中一个特定于该细胞的部分，被称为细胞的“放电区域”。我们在此证明，放电在时间域上远不如在位置域上可靠。将通过放电区域时的放电情况与一个模型进行了比较，该模型中位置特异性放电的泊松方差由时间平均的位置放电率分布决定。与随机模型的预期相比，位置细胞通常放电过少或过多。位置细胞的这一基本特性被称为“过度放电方差”，它有三个主要影响：（i）位置细胞的放电不仅是由许多小的、异步的兴奋性突触输入的总和所驱动。（ii）位置细胞放电可能除了对当前头部位置进行编码外，还对一个信号进行编码。（iii）过度放电方差有助于解释为什么根据许多位置细胞的同时活动来计算大鼠位置时误差较大。
The idea that the rat hippocampus stores a map of space is based on the existence of "place cells" that show "location-specific" firing. The discharge of place cells is confined with remarkable precision to a cell-specific part of the environment called the cell's "firing field." We demonstrate here that firing is not nearly as reliable in the time domain as in the positional domain, Discharge during passes through the firing field was compared with a model with Poisson variance of the location-specific firing determined by the time-averaged positional firing rate distribution. Place cells characteristically fire too little or too much compared with expectations from the random model. This fundamental property of place cells is referred to as "excess firing variance" and has three main implications: (i) Place cell discharge is not only driven by the summation of many small, asynchronous excitatory synaptic inputs. (ii) Place cell discharge may encode a signal in addition to the current head location. (iii) The excess firing variance helps explain why the errors in computing the rat's position from the simultaneous activity of many place cells are large.