人们早就假设，在内嗅皮层中，当一个动物穿过其环境运动时，网格细胞需要关于动物跑动速度的信息来正确编码周期性空间放电场(spatial firing fields)。然而，这种信号传输速度信息的来源以前却没有被识别出。在这项研究中，Edvard Moser及同事在内嗅皮层(MEC)中分离出根据神经放电速度线性编码跑动速度的一个特定类别的神经元。这些 “速度细胞”与其他具有特定功能的MEC神经元截然不同，以独立于周围环境的方式编码速度。
原文内容：Grid cells in the medial entorhinal cortex have spatial firing fields that repeat periodically in a hexagonal pattern. When animals move, activity is translated between grid cells in accordance with the animal’s displacement in the environment. For this translation to occur, grid cells must have continuous access to information about instantaneous running speed. However, a powerful entorhinal speed signal has not been identified. Here we show that running speed is represented in the firing rate of a ubiquitous but functionally dedicated population of entorhinal neurons distinct from other cell populations of the local circuit, such as grid, head-direction and border cells. These ‘speed cells’ are characterized by a context-invariant positive, linear response to running speed, and share with grid cells a prospective bias of ~50–80 ms. Our observations point to speed cells as a key component of the dynamic representation of self-location in the medial entorhinal cortex.
原文地址：http://www.nature.com/nature/journal/v523/n7561/full/nature14622.html