Anatomical Organization and Spatiotemporal Firing Patterns of Layer 3 Neurons in the Rat Medial Entorhinal Cortex
Anatomical Organization and Spatiotemporal Firing Patterns of Layer 3 Neurons in the Rat Medial Entorhinal Cortex
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DOI：
10.1523/jneurosci.0696-15.2015
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发表时间：
2015-09-09
影响因子：
5.3
通讯作者：
Burgalossi, Andrea
中科院分区：
文献类型：
--
作者：
Tang, Qiusong;Ebbesen, Christian Laut;Burgalossi, Andrea
内侧内嗅皮层的第3层是从新皮层到海马的主要通道。在这里，我们解决了结构-功能的关系，内侧内嗅皮层第3层结合解剖分析与单神经元的单细胞鉴定在自由行为的大鼠。在解剖学上，第3层表现为相对均匀的细胞片层。双逆行神经元追踪实验表明，第3层锥体细胞群，其中项目同侧海马，和对侧内侧内嗅皮质之间的大重叠。这些细胞混合在第3层内，具有相似的形态学和内在电生理特性。第3层神经元的树突树在很大程度上避免了第2层的钙结合蛋白阳性斑块。在空间探索（n = 17）和细胞外记录（n = 52）的第3层神经元的识别指向均匀的空间放电模式。第3层神经元仅表现出较弱的尖峰theta节律和稀疏的头向选择性。大多数细胞（69个中的50个）没有显示出显著的空间调制。所有的类似28%的神经元携带大量的空间信息（69个中的19个）以不规则的空间模式放电。因此，第3层的时空发射性能显着不同的第2层，其中θ节律是突出的和空间调制的细胞往往在网格或边界模式放电。
Layer 3 of the medial entorhinal cortex is a major gateway from the neocortex to the hippocampus. Here we addressed structure-function relationships in medial entorhinal cortex layer 3 by combining anatomical analysis with juxtacellular identification of single neurons in freely behaving rats. Anatomically, layer 3 appears as a relatively homogeneous cell sheet. Dual-retrograde neuronal tracing experiments indicate a large overlap between layer 3 pyramidal populations, which project to ipsilateral hippocampus, and the contralateral medial entorhinal cortex. These cells were intermingled within layer 3, and had similar morphological and intrinsic electrophysiological properties. Dendritic trees of layer 3 neurons largely avoided the calbindin-positive patches in layer 2. Identification of layer 3 neurons during spatial exploration (n = 17) and extracellular recordings (n = 52) pointed to homogeneous spatial discharge patterns. Layer 3 neurons showed only weak spiking theta rhythmicity and sparse head-direction selectivity. A majority of cells (50 of 69) showed no significant spatial modulation. All of the similar to 28% of neurons that carried significant amounts of spatial information (19 of 69) discharged in irregular spatial patterns. Thus, layer 3 spatiotemporal firing properties are remarkably different from those of layer 2, where theta rhythmicity is prominent and spatially modulated cells often discharge in grid or border patterns.