Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.
Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.
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DOI：
10.1002/hipo.22559
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发表时间：
2016-06
期刊：
影响因子：
3.5
通讯作者：
Soltesz I
中科院分区：
文献类型：
--
作者：
Armstrong C;Wang J;Yeun Lee S;Broderick J;Bezaire MJ;Lee SH;Soltesz I
内侧内嗅皮层第二层（MEClayerII）是空间导航和记忆的关键脑区，它也证明了颞叶癫痫（TLE）患者和动物模型的一些变化。先前对MEClayerII中GABA能微电路的研究表明，含胆囊收缩素的篮状细胞（CCKBC）根据突触后主细胞的长程投射模式选择其靶点。具体而言，CCKBC在很大程度上避免了含reelin的主细胞，形成穿通路径的同侧齿状回和优先支配非穿通路径形成含钙结合蛋白的主细胞。我们研究了包含小白蛋白的篮状细胞（PVBC），另一个主要的体周靶向GABA能细胞群，是否也表现出类似的突触后靶点选择性。此外，我们测试的假设，电路选择性的功能或解剖结构的安排被破坏在MEClayerII在慢性TLE，使用重复的低剂量红藻氨酸模型大鼠。在对照动物中，我们发现PVBCs支配两个主要细胞群，但也有显着的选择性含钙结合蛋白的主细胞MEClayerII。然而，这种偏好的程度小于CCKBC。此外，轴突追踪和配对记录表明，个别PVBC能够接触钙结合蛋白和reelin含有主细胞。在慢性癫痫动物中，我们发现两个主要细胞群的内在特性，GABA能体周扣顿数和CCKBC和PVBC的选择性在MEClayerII中保持显著恒定。然而，微型IPSC频率降低癫痫，成对的录音显示存在的直接兴奋性连接的主要细胞之间的MEClayerII癫痫，这是不寻常的正常成人MEClayerII。总之，这些发现推进了我们对控制和癫痫动物的体周抑制组织的认识。
The medial entorhinal cortex layer II (MEClayerII) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII. However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII. However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII. Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals.