Sanders Honi, Rennó-Costa César, Idiart Marco, Lisman John
Volen Center for Complex Systems, Brandeis University, Waltham, MA 02454, USA.
Brain Institute, Federal University of Rio Grande do Norte, Natal, RN 59066, Brazil.
Trends Neurosci. 2015 Dec;38(12):763-775. doi: 10.1016/j.tins.2015.10.004. Epub 2015 Nov 24.
Much has been learned about the hippocampal/entorhinal system, but an overview of how its parts work in an integrated way is lacking. One question regards the function of entorhinal grid cells. We propose here that their fundamental function is to provide a coordinate system for producing mind-travel in the hippocampus, a process that accesses associations with upcoming positions. We further propose that mind-travel occurs during the second half of each theta cycle. By contrast, the first half of each theta cycle is devoted to computing current position using sensory information from the lateral entorhinal cortex (LEC) and path integration information from the medial entorhinal cortex (MEC). This model explains why MEC lesions can abolish hippocampal phase precession but not place fields.
关于海马体/内嗅系统，我们已经了解了很多，但仍缺乏对其各部分如何以整合方式运作的概述。一个问题涉及内嗅网格细胞的功能。我们在此提出，它们的基本功能是为海马体中产生思维游走提供一个坐标系，这一过程可获取与即将到来的位置的关联。我们进一步提出，思维游走发生在每个θ周期的后半段。相比之下，每个θ周期的前半段则致力于利用来自外侧内嗅皮质（LEC）的感觉信息和来自内侧内嗅皮质（MEC）的路径整合信息来计算当前位置。该模型解释了为什么MEC损伤会消除海马体相位进动，但不会消除位置野。
