Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Proc Natl Acad Sci U S A. 2010 Apr 6;107(14):6487-92. doi: 10.1073/pnas.0911213107. Epub 2010 Mar 22.
Finding our way in spatial environments is an essential part of daily life. How do we come to possess this sense of direction? Extensive research points to the hippocampus and entorhinal cortex (EC) as key neural structures underlying spatial navigation. To better understand this system, we examined recordings of single-neuron activity from neurosurgical patients playing a virtual-navigation video game. In addition to place cells, which encode the current virtual location, we describe a unique cell type, EC path cells, the activity of which indicates whether the patient is taking a clockwise or counterclockwise path around the virtual square road. We find that many EC path cells exhibit this directional activity throughout the environment, in contrast to hippocampal neurons, which primarily encode information about specific locations. More broadly, these findings support the hypothesis that EC encodes general properties of the current context (e.g., location or direction) that are used by hippocampus to build unique representations reflecting combinations of these properties.
在空间环境中找到方向是日常生活的重要组成部分。我们是如何拥有这种方向感的呢？大量研究指出，海马体和内嗅皮层（entorhinal cortex，EC）是空间导航的关键神经结构。为了更好地理解这个系统，我们对接受神经外科手术的患者在玩虚拟导航视频游戏时的单个神经元活动进行了记录。除了编码当前虚拟位置的位置细胞（place cells）外，我们还描述了一种独特的细胞类型，即 EC 路径细胞（EC path cells），其活动表明患者正在沿着虚拟广场路顺时针还是逆时针行进。我们发现，许多 EC 路径细胞在整个环境中表现出这种定向活动，而海马体神经元则主要编码关于特定位置的信息。更广泛地说，这些发现支持了这样一种假设，即 EC 编码当前环境的一般属性（例如位置或方向），而海马体则利用这些属性来构建反映这些属性组合的独特表示。
