Synaptic specializations exist between enteric motor nerves and interstitial cells of Cajal in the murine stomach
Synaptic specializations exist between enteric motor nerves and interstitial cells of Cajal in the murine stomach
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DOI：
10.1002/cne.20746
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发表时间：
2005-12-12
影响因子：
2.5
通讯作者：
Ward, SM
中科院分区：
文献类型：
--
作者：
Beckett, EAH;Takeda, Y;Ward, SM
自主神经传递被认为是通过神经曲张和平滑肌细胞之间的松散联系发生的。在胃肠道中，超微结构研究已经证明胃和结肠中的肠神经和肌内Cajal间质细胞（ICC-IM）与小肠的深肌丛（ICC-IM）中的ICC之间的紧密并置。在没有ICC-IM的情况下，连接后神经反应受到损害。虽然已经报道了神经和ICC-IM之间的膜特化，但这些特化的分子身份尚未研究。在这里，我们的特点是在小鼠胃神经末梢和ICC-IM之间的突触相关蛋白的表达和分布。检测突触前蛋白synaptotagmin、syntaxin和SNAP-25的转录本。Synaptotagmin和SNAP-25免疫阳性的神经曲张集中在运动神经的曲张区域，并与ICC-IM紧密贴壁，但不与平滑肌贴壁。W/W-V小鼠用于检查在不存在ICC-IM的情况下突触蛋白的表达和分布。在W/W-V组织中检测到编码synaptotagmin、syntaxin和SNAP-25的转录物。在ICC-IM的情况下，synaptotagmin和SNAP-25定位于神经静脉曲张。逆转录聚合酶链反应（RT-PCR）和免疫组化结果显示，W/W-V突变体中突触后密度蛋白PSD-93和PSD-95在胃中表达减少。这些数据支持肠神经和胃组织中ICC-IM之间存在突触特化。在没有ICC-IM的情况下，突触囊泡对接和融合机制的组分被运输并集中在肠神经末梢中。
Autonomic neurotransmission is thought to occur via a loose association between nerve varicosities and smooth muscle cells. In the gastrointestinal tract ultrastructural studies have demonstrated close apposition between enteric nerves and intramuscular interstitial cells of Cajal (ICC-IM) in the stomach and colon and ICC in the deep muscular plexus (ICC-DMP) of the small intestine. In the absence of ICC-IM, postjunctional neural responses are compromised. Although membrane specializations between nerves and ICC-IM have been reported, the molecular identity of these specializations has not been studied. Here we have characterized the expression and distribution of synapse-associated proteins between nerve terminals and ICC-IM in the murine stomach. Transcripts for the presynaptic proteins synaptotagmin, syntaxin, and SNAP-25 were detected. Synaptotagmin and SNAP-25-immunopositive nerve varicosities were concentrated in varicose regions of motor nerves and were closely apposed to ICC-IM but not smooth muscle. W/W-V mice were used to examine the expression and distribution of synaptic proteins in the absence of ICC-IM. Transcripts encoding synaptotagmin, syntaxin, and SNAP-25 were detected in W/W-V tissues. In the absence of ICC-IM, synaptotagmin and SNAP-25 were localized to nerve varicosities. Reverse transcriptase polymer chain reaction (RT-PCR) and immunohistochemistry demonstrated the expression of postsynaptic density proteins PSD-93 and PSD-95 in the stomach and expression levels of PSD-93 and PSD-95 were reduced in W/W-V mutants. These data support the existence of synaptic specializations between enteric nerves and ICC-IM in gastric tissues. In the absence of ICC-IM, components of the synaptic vesicle docking and fusion machinery is trafficked and concentrated in enteric nerve terminals.