PROXIMITY OF EXCITATORY SYNAPSES AND ASTROGLIAL GAP JUNCTIONS IN LAYER IV OF THE MOUSE BARREL CORTEX
PROXIMITY OF EXCITATORY SYNAPSES AND ASTROGLIAL GAP JUNCTIONS IN LAYER IV OF THE MOUSE BARREL CORTEX
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DOI：
10.1016/j.neuroscience.2015.01.051
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发表时间：
2015-04-16
期刊：
影响因子：
3.3
通讯作者：
Giaume, C.
中科院分区：
文献类型：
--
作者：
Genoud, C.;Houades, V.;Giaume, C.
神经元和星形胶质细胞是成人大脑中的两个主要细胞群，它们的特点是它们各自的细胞间通讯模式——突触和间隙连接（GJ）。此外，越来越多的证据表明，动态和代谢性神经胶质相互作用导致所谓的“三方突触”突触传递的调节。在此基础上，我们在超微结构水平上研究了成年小鼠桶状皮层第四层兴奋性突触（ES）和星形胶质细胞GJ的空间分布。我们使用连接蛋白（Cx） 30和43的特异性抗体来鉴定星形胶质GJ，已知这两种蛋白存在于大脑皮层的大多数星形胶质GJ中。在电子显微镜图像中，我们测量了两个ES之间的距离，两个GJ之间的距离，以及GJ与其最近的ES之间的距离。我们发现在空心区和间隔区，每3个ES中有2个GJ。考虑到星形胶质细胞结构域的大小，GJ的高密度提示存在反射型，即同一星形胶质细胞的进程之间存在GJ。有趣的是，ES和星形胶质GJ之间的距离明显低于两个突触之间或两个GJ之间的距离。这些观察结果表明，这两种细胞间通讯模式在桶状皮层的第四层并不是随机分布的。因此，这一特征可能为最近报道的神经元回路和星形胶质网络之间的功能相互作用提供形态学支持。(c) 2015年。Elsevier Ltd.出版。版权所有。
Neurons and astrocytes, the two major cell populations in the adult brain, are characterized by their own mode of intercellular communication - the synapses and the gap junctions (GJ), respectively. In addition, there is increasing evidence for dynamic and metabolic neuroglial interactions resulting in the modulation of synaptic transmission at the so-called "tripartite synapse". Based on this, we have investigated at the ultrastructural level how excitatory synapses (ES) and astroglial GJ are spatially distributed in layer IV of the barrel cortex of the adult mouse. We used specific antibodies for connexin (Cx) 30 and 43 to identify astroglial GJ, these two proteins are known to be present in the majority of astroglial GJ in the cerebral cortex. In electron-microscopic images, we measured the distance between two ES, between two GJ and between a GJ and its nearest ES. We found a ratio of two GJ per three ES in the hollow and septal areas. Taking into account the size of an astrocyte domain, the high density of GJ suggests the occurrence of reflexive type, i.e. GJ between processes of the same astrocyte. Interestingly, the distance between an ES and an astroglial GJ was found to be significantly lower than that between either two synapses or between two GJ. These observations indicate that the two modes of cell-to-cell communication are not randomly distributed in layer IV of the barrel cortex. Consequently, this feature may provide the morphological support for the recently reported functional interactions between neuronal circuits and astroglial networks. (C) 2015 IBRO. Published by Elsevier Ltd. All rights reserved.