Grid Cell Mechanisms and Function: Contributions of Entorhinal Persistent Spiking and Phase Resetting
Grid Cell Mechanisms and Function: Contributions of Entorhinal Persistent Spiking and Phase Resetting
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DOI：
10.1002/hipo.20512
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发表时间：
2008-01-01
期刊：
影响因子：
3.5
通讯作者：
Hasselmo, Michael E.
中科院分区：
文献类型：
--
作者：
Hasselmo, Michael E.
本文提出了一个网格细胞放电模型的基础上的内在持续放电实验所示的内嗅皮层神经元。在这个模型中，持续放电的机制允许单个神经元保持稳定的基线放电频率。从速度调制的头部方向细胞的去极化输入瞬时转移的频率从基线的发射，导致在尖峰相位的位移成比例的速度的积分。来自不同持续放电神经元的输入的收敛仅在持续放电神经元在相似的相位范围内时才在网格单元中引起尖峰。该模型有效地模拟了开放场环境中网格单元的二维发射，以及θ相位进动的特性。该模型提供了振荡干扰模型的替代实现。持续放电还可以在回路水平上与节律性抑制和显示膜电位振荡的神经元相互作用，以尖峰相位编码位置。这些机制可以与从刺激的视角和距离计算位置并行操作。除了模拟二维网格模式，相位干扰模型还可以解释其他任务中的上下文相关发射。在内嗅皮层、海马和后下托的网络模拟中，相位的重置有效地复制了在执行连续空间交替任务期间内嗅和海马神经元的上下文依赖性放电，所述连续空间交替任务是在延迟期期间在轮中运行的延迟空间交替任务（Pastalkova等人，Science，2008）和发夹迷宫任务。(C)2008 Wiley-Liss，Inc.
This article presents a model of grid cell firing based on the intrinsic persistent firing shown experimentally in neurons of entorhinal cortex. in this model, the mechanism of persistent firing allows individual neurons to hold a stable baseline firing frequency. Depolarizing input from speed-modulated head direction cells transiently shifts the frequency of firing from baseline, resulting in a shift in spiking phase in proportion to the integral of velocity. The convergence of input from different persistent firing neurons causes spiking in a grid cell only when the persistent firing neurons are, within similar phase ranges. This model effectively simulates the two-dimensional firing of grid cells in open field environments, as well as the properties of theta phase precession. This model provides an alternate implementation of oscillatory interference models. The persistent firing could also interact on a circuit level with rhythmic inhibition and neurons showing membrane potential oscillations to code position with spiking phase. These mechanisms could operate in parallel with computation of position from visual angle and distance of stimuli. In addition to simulating two-dimensional grid patterns, models of phase interference can account for context-dependent firing in other tasks. In network simulations of entorhinal cortex, hippocampus, and postsubiculum, the reset of phase effectively replicates context-dependent firing by entorhinal and hippocampal neurons during performance of a continuous spatial alternation task, a delayed spatial alternation task with running in a wheel during the delay period (Pastalkova et al., Science, 2008), and a hairpin maze task. (C) 2008 Wiley-Liss, Inc.