LOCALIZATION OF α7 NICOTINIC ACETYLCHOLINE RECEPTOR IMMUNOREACTIVITY ON GABAERGIC INTERNEURONS IN LAYERS I-III OF THE RAT RETROSPLENIAL GRANULAR CORTEX
LOCALIZATION OF α7 NICOTINIC ACETYLCHOLINE RECEPTOR IMMUNOREACTIVITY ON GABAERGIC INTERNEURONS IN LAYERS I-III OF THE RAT RETROSPLENIAL GRANULAR CORTEX
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DOI：
10.1016/j.neuroscience.2013.08.024
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发表时间：
2013-11-12
期刊：
影响因子：
3.3
通讯作者：
Sato, F.
中科院分区：
文献类型：
--
作者：
Murakami, K.;Ishikawa, Y.;Sato, F.
大鼠压后颗粒皮质（RSG）接受来自胆碱能基底前脑（CBF）内侧隔-斜角带（MS-DB）的胆碱能输入，投射终止于RSG的I-III层。乙酰胆碱（ACh）对这些层中的皮质GABA能中间神经元的调节作用由α 7烟碱乙酰胆碱受体（α 7 nAChRs）介导。α 7 nAChR在大脑皮层中最丰富，并且主要定位于GABA能中间神经元。然而，CBF投射到RSG还没有被详细研究，α 7 nAChRs在大鼠RSG中的细胞或亚细胞分布仍然不清楚。本研究的主要目的是测试，α 7 nAChRs驻留在大鼠RSG的CBF终末野的GABA能中间神经元上。首先，我们开始使用顺行神经追踪和胆碱能标记物的免疫组织化学标记来定义从MS-DB到RSG层的CBF投射的特征。这些结果表明，轴突终末标记的模式在层的RSG的Ia，以及层II/III是非常相似的胆碱能轴突在RSG的模式。接下来，我们研究了α 7 nAChR之间的关系，使用α-银环蛇毒素或α 7 nAChR抗体标记，和局部神经化学环境，通过标记周围的细胞与抗体对谷氨酸脱羧酶（GAD），小清蛋白（PV）和reelin（离子型5-羟色胺受体表达GABA能中间神经元的标记物）。发现α 7 nAChR定位于RSG的I-III层中GABA能PV-、reelin-染色和非PV-染色神经元的亚群内的体树突和神经元元件上。最后，电子显微镜显示，α 7 nAChRs是GAD和PV阳性细胞质和神经元元素。这些结果有力地表明，ACh从CBF传入释放通过α 7 nAChR传输到GAD-，PV-和reelin阳性GABA能中间神经元层的RSG。(C)2013年IBRO。由爱思唯尔有限公司出版。保留所有权利。
The rat retrosplenial granular cortex (RSG) receives cholinergic input from the medial septum-diagonal band (MS-DB) of the cholinergic basal forebrain (CBF), with projections terminating in layers I-III of RSG. The modulatory effects of acetylcholine (ACh) on cortical GABAergic interneurons in these layers are mediated by alpha 7 nicotinic acetylcholine receptors (alpha 7nAChRs). alpha 7nAChRs are most abundant in the cerebral cortex and are largely localized to GABAergic interneurons. However, the CBF projection to the RSG has not been studied in detail, and the cellular or subcellular distribution of alpha 7nAChRs in the rat RSG remains unclear. The main objective of this study was to test that alpha 7nAChRs reside on GABAergic interneurons in CBF terminal fields of the rat RSG. First, we set out to define the characteristics of CBF projections from the MS-DB to layers of the RSG using anterograde neural tracing and immunohistochemical labeling with cholinergic markers. These results revealed that the pattern of axon terminal labeling in layer la, as well as layer II/III of the RSG is remarkably similar to the pattern of cholinergic axons in the RSG. Next, we investigated the relationship between alpha 7nAChRs, labeled using either alpha-bungarotoxin or alpha 7nAChR antibody, and the local neurochemical environment by labeling surrounding cells with antibodies against glutamic acid decarboxylase (GAD), parvalbumin (PV) and reelin (a marker of the ionotropic serotonin receptor-expressing GABAergic interneurons). alpha 7nAChRs were found to be localized on both somatodendritic and neuronal elements within subpopulations of GABAergic PV-, reelin-stained and non PV-stained neurons in layers I-III of the RSG. Finally, electron microscopy revealed that alpha 7nAChRs are GAD- and PV-positive cytoplasmic and neuronal elements. These results strongly suggest that ACh released from CBF afferents is transmitted via alpha 7nAChR to GAD-, PV-, and reelin-positive GABAergic interneurons in layers of the RSG. (C) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.