Bernstein Center for Computational Neuroscience, Humboldt University of Berlin, Philippstrasse 13 Haus 6, 10115 Berlin, Germany.
Science. 2014 Feb 21;343(6173):891-6. doi: 10.1126/science.1243028. Epub 2014 Jan 23.
Little is known about how microcircuits are organized in layer 2 of the medial entorhinal cortex. We visualized principal cell microcircuits and determined cellular theta-rhythmicity in freely moving rats. Non-dentate-projecting, calbindin-positive pyramidal cells bundled dendrites together and formed patches arranged in a hexagonal grid aligned to layer 1 axons, parasubiculum, and cholinergic inputs. Calbindin-negative, dentate-gyrus-projecting stellate cells were distributed across layer 2 but avoided centers of calbindin-positive patches. Cholinergic drive sustained theta-rhythmicity, which was twofold stronger in pyramidal than in stellate neurons. Theta-rhythmicity was cell-type-specific but not distributed as expected from cell-intrinsic properties. Layer 2 divides into a weakly theta-locked stellate cell lattice and spatiotemporally highly organized pyramidal grid. It needs to be assessed how these two distinct principal cell networks contribute to grid cell activity.
关于内侧缰核皮层 2 层中的微电路是如何组织的，我们知之甚少。我们在自由活动的大鼠中可视化了主要细胞微电路，并确定了细胞的θ节律性。非齿状投射、钙结合蛋白阳性的锥体细胞将树突捆绑在一起，并形成呈六边形网格排列的斑块，与 1 层轴突、副隔核和胆碱能输入对齐。钙结合蛋白阴性、齿状回投射的星状细胞分布在 2 层，但避开钙结合蛋白阳性斑块的中心。胆碱能驱动维持θ节律性，在锥体细胞中比在星状神经元中要强两倍。θ节律性是细胞类型特异性的，但不按细胞内在特性预期的方式分布。2 层分为弱θ锁定的星状细胞晶格和时空上高度组织的锥状网格。需要评估这两个不同的主要细胞网络如何对网格细胞活动做出贡献。
