Ionic current correlations underlie the global tuning of large numbers of neuronal activity attributes.
Ionic current correlations underlie the global tuning of large numbers of neuronal activity attributes.
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DOI：
10.1523/jneurosci.6500-11.2012
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发表时间：
2012-09-26
期刊：
影响因子：
--
通讯作者：
Golowasch J
中科院分区：
文献类型：
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作者：
Zhao S;Golowasch J
离子电导在确定的神经元是高度可变的。这就提出了这样的神经元如何产生稳定活动的关键问题。在不同系统中越来越多的神经元中已经观察到离子电流的共表达，这表明离子通道表达的共调节，通过因此连接它们的可变性，可以使神经元保持相对恒定的神经元活性，如许多最近的理论研究所建议的。我们研究这一假设实验使用的电压和动态钳技术，首先测量，然后修改的离子电导水平的三个电流中确定的神经元的螃蟹幽门网络。我们通过测量十个不同的属性（振荡周期，尖峰频率等）来量化活动，并发现电导对和三联体之间的线性、正和负关系，其可以使幽门神经元保持活动属性不变。与实验观察结果一致，一些最严格的调节功能似乎是爆发活动的相位关系。我们的结论是，离子电导的共同变化（可能是一个严格控制的共同调节）可以帮助神经元保持神经元活动的某些属性不变，而在同一时间允许电导在很宽的范围内变化，以响应内部或环境的输入和扰动。我们的研究结果还表明，神经元可以调整神经元活动的全局通过协调表达的离子电流。
Ionic conductances in identified neurons are highly variable. This poses the crucial question of how such neurons can produce stable activity. Co-expression of ionic currents have been observed in an increasing number of neurons in different systems, suggesting that the co-regulation of ionic channel expression, by thus linking their variability, may enable neurons to maintain relatively constant neuronal activity as suggested by a number of recent theoretical studies. We examine this hypothesis experimentally using the voltage- and dynamic-clamp techniques to first measure and then modify the ionic conductance levels of three currents in identified neurons of the crab pyloric network. We quantify activity by measuring ten different attributes (oscillation period, spiking frequency, etc.), and find linear, positive and negative relationships between conductance pairs and triplets that can enable pyloric neurons to maintain activity attributes invariant. Consistent with experimental observations some of the features most tightly regulated appear to be phase relationships of bursting activity. We conclude that co-variation (and probably a tightly controlled co-regulation) of ionic conductances can help neurons maintain certain attributes of neuronal activity invariant while at the same time allowing conductances to change over wide ranges in response to internal or environmental inputs and perturbations. Our results also show that neurons can tune neuronal activity globally via coordinate expression of ion currents.