人們早就假設(shè)，在內(nèi)嗅皮層中，當(dāng)一個動物穿過其環(huán)境運(yùn)動時，網(wǎng)格細(xì)胞需要關(guān)于動物跑動速度的信息來正確編碼周期性空間放電場(spatial firing fields)。然而，這種信號傳輸速度信息的來源以前卻沒有被識別出。在這項研究中，Edvard Moser及同事在內(nèi)嗅皮層(MEC)中分離出根據(jù)神經(jīng)放電速度線性編碼跑動速度的一個特定類別的神經(jīng)元。這些 “速度細(xì)胞”與其他具有特定功能的MEC神經(jīng)元截然不同，以獨(dú)立于周圍環(huán)境的方式編碼速度。

原文內(nèi)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