Ectopic expression of select innexins in individual central neurons couples them to pre-existing neuronal or glial networks that express the same innexin.
Ectopic expression of select innexins in individual central neurons couples them to pre-existing neuronal or glial networks that express the same innexin.
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DOI：
10.1523/jneurosci.2693-12.2012
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发表时间：
2012-10-10
期刊：
影响因子：
--
通讯作者：
Baker MW
中科院分区：
文献类型：
--
作者：
Firme CP 3rd;Natan RG;Yazdani N;Macagno ER;Baker MW
在药用水蛭毛水蛭（Hirudo verbana）基因组中发现的21个连接蛋白（Inx）基因（Hve-inx）中有15个在CNS中表达。两个是泛神经元表达，而其他的是限制在他们的表达，以少量的细胞，在某些情况下，反映了已知的电耦合和染料耦合的神经元或神经胶质细胞的网络的成员。我们在这里报告说，当Hve-inx基因特征的离散耦合网络异位表达在已知不表达它们的神经元，实验细胞被发现成为染料耦合与该网络中的其他细胞。Hve-inx 6通常仅由每个神经节中的三个神经元表达，它们彼此形成强烈的染料偶联电连接[缩短-偶联中间神经元（S-CI）网络]。但是，当Hve-inx 6异位表达在各种中央胚胎神经元，这些细胞成为染料耦合的S-CI网络。同样，Hve-inx 2通常由神经节的大胶质细胞独特表达，但当它在不同的中枢神经元中异位表达时，它们会与胶质细胞发生染料偶联。相反，泛神经元Inx基因Hve-inx 1和Hve-inx 14的过表达没有产生任何新的染料偶联到预先存在的神经元网络的情况。这些结果表明，某些连接蛋白的表达足以将单个神经元与CNS中预先存在的网络偶联。我们建议，选择性神经元连接和电路形成的水蛭的主要决定因素是独特的间隙连接蛋白的子集的表面表达。
Fifteen of the 21 innexin (Inx) genes (Hve-inx) found in the genome of the medicinal leech, Hirudo verbana, are expressed in the CNS. Two are expressed pan-neuronally, while the others are restricted in their expression to small numbers of cells, in some cases reflecting the membership of known networks of electrically coupled and dye-coupled neurons or glial cells. We report here that when Hve-inx genes characteristic of discrete coupled networks were expressed ectopically in neurons known not to express them, the experimental cells were found to become dye coupled with the other cells in that network. Hve-inx6 is normally expressed by only three neurons in each ganglion, which form strongly dye-coupled electrical connections with each other [Shortening-Coupling interneuron (S-CI) network]. But when Hve-inx6 was ectopically expressed in a variety of central embryonic neurons, those cells became dye coupled with the S-CI network. Similarly, Hve-inx2 is normally uniquely expressed by the ganglion’s large glial cells, but when it was ectopically expressed in different central neurons, they became dye coupled to the glial cells. In contrast, overexpression of the pan-neuronal Inx genes Hve-inx1 and Hve-inx14 did not yield any novel instances of dye coupling to pre-existent neuronal networks. These results reveal that expression of certain innexins is sufficient to couple individual neurons to pre-existing networks in the CNS. We propose that a primary determinant of selective neuronal connectivity and circuit formation in the leech is the surface expression of unique subsets of gap junctional proteins.