Ephaptic interactions in the mammalian olfactory system
Ephaptic interactions in the mammalian olfactory system
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DOI：
10.1523/jneurosci.21-20-j0004.2001
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发表时间：
2001-10-15
影响因子：
5.3
通讯作者：
Keller, A
中科院分区：
文献类型：
--
作者：
Bokil, H;Laaris, N;Keller, A
触觉耦合是指由流经细胞外空间的电流介导的神经元之间的相互作用。由于相对较大的细胞外空间和分隔大多数轴突的髓磷脂层，轴突之间的突触相互作用被认为可以忽略不计。相比之下，嗅神经轴突没有髓鞘，排列成紧密的束，这一特征可能会增强触觉耦合。我们使用计算方法测试了哺乳动物嗅觉神经中发生触觉相互作用的假设。轴突束模型的数值解表明，一系列生理相关参数会发生显着的触觉相互作用。单个轴突中的动作电位可以激发束中所有其他轴突的动作电位。触觉相互作用还可以导致独立刺激的轴突同步放电。我们的研究结果表明，触觉相互作用可能是嗅觉密码的重要决定因素，并且这种相互作用可能发生在其他类似组织的轴突或树突束中。
Ephaptic coupling refers to interactions between neurons mediated by current flow through the extracellular space. Ephaptic interactions between axons are considered negligible, because of the relatively large extracellular space and the layers of myelin that separate most axons. By contrast, olfactory nerve axons are unmyelinated and arranged in tightly packed bundles, features that may enhance ephaptic coupling. We tested the hypothesis that ephaptic interactions occur in the mammalian olfactory nerve with the use of a computational approach. Numerical solutions of models of axon fascicles show that significant ephaptic interactions occur for a range of physiologically relevant parameters. An action potential in a single axon can evoke action potentials in all other axons in the fascicle. Ephaptic interactions can also lead to synchronized firing of independently stimulated axons. Our findings suggest that ephaptic interactions may be significant determinants of the olfactory code and that such interactions may occur in other, similarly organized axonal or dendritic bundles.