A supercritical density of Na(+) channels ensures fast signaling in GABAergic interneuron axons.
A supercritical density of Na(+) channels ensures fast signaling in GABAergic interneuron axons.
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DOI：
10.1038/nn.3678
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发表时间：
2014-05
影响因子：
25
通讯作者：
Jonas, Peter
中科院分区：
文献类型：
--
作者：
Hu, Hua;Jonas, Peter
快速尖峰，小白蛋白表达GABA能中间神经元/篮细胞（BC）在前馈和反馈抑制，γ振荡和复杂的信息处理中发挥关键作用。对于这些功能，动作电位（AP）从索马到突触前末梢的快速传播是重要的。然而，中间神经元轴突的功能特性仍然难以捉摸。在这里，我们研究了共焦靶向亚细胞膜片钳记录在大鼠海马脑片的中间神经元轴突。AP起始于距索马体约20 μm的近端轴突，并以较高的可靠性和速度向远端轴突传播。亚细胞定位显示从索马到近端轴突的Na+电导密度逐步增加，然后在远端轴突进一步逐渐增加。主动电缆建模和实验与部分通道阻断表明，低轴突Na+电导密度是足够的可靠性，但高Na+密度是必要的传播速度和快速尖峰AP表型。我们的研究结果表明，超临界密度的Na+通道补偿了中间神经元轴突的形态学特性（小的节段直径，广泛的分支，和高的终扣密度），确保快速AP传播和高频重复放电。
Fast-spiking, parvalbumin-expressing GABAergic interneurons/basket cells (BCs) play a key role in feedforward and feedback inhibition, gamma oscillations, and complex information processing. For these functions, fast propagation of action potentials (APs) from the soma to the presynaptic terminals is important. However, the functional properties of interneuron axons remain elusive. Here, we examined interneuron axons by confocally targeted subcellular patch-clamp recording in rat hippocampal slices. APs were initiated in the proximal axon ~20 μm from the soma, and propagated to the distal axon with high reliability and speed. Subcellular mapping revealed a stepwise increase of Na+ conductance density from the soma to the proximal axon, followed by a further gradual increase in the distal axon. Active cable modeling and experiments with partial channel block indicated that low axonal Na+ conductance density was sufficient for reliability, but high Na+ density was necessary for both speed of propagation and fast-spiking AP phenotype. Our results suggest that a supercritical density of Na+ channels compensates for the morphological properties of interneuron axons (small segmental diameter, extensive branching, and high bouton density), ensuring fast AP propagation and high-frequency repetitive firing.
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DOI：
10.1523/jneurosci.6044-08.2009
发表时间：
2009-06-10
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
de Almeida L;Idiart M;Lisman JE
通讯作者：
Lisman JE
影响因子：
5.5
作者：
HODGKIN, AL;HUXLEY, AF
通讯作者：
HUXLEY, AF
影响因子：
56.9
作者：
Alle, Henrik;Roth, Arnd;Geiger, Joerg R. P.
通讯作者：
Geiger, Joerg R. P.
哺乳动物神经元动作电位期间的钠进入：快速刺激神经元的灭活不完全失活和代谢效率降低。
影响因子：
16.2
作者：
Carter, Brett C.;Bean, Bruce P.
通讯作者：
Bean, Bruce P.
影响因子：
3.8
作者：
GOLDMAN, L;SCHAUF, CL
通讯作者：
SCHAUF, CL