Spontaneous Spiking Is Governed by Broadband Fluctuations
Spontaneous Spiking Is Governed by Broadband Fluctuations
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DOI：
10.1523/jneurosci.1899-21.2022
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发表时间：
2022-06-29
影响因子：
5.3
通讯作者：
Reynolds, John H.
中科院分区：
文献类型：
--
作者：
Davis, Zachary W.;Muller, Lyle;Reynolds, John H.
皮质神经元群体在其持续的自发活动中产生节律性波动。这些波动可以在局部场电位（LFP）中看到，其反映了来自记录电极附近的局部群体中的突触活动的总返回电流。LFP的光谱很宽，许多研究人员认为这个宽度包含许多可能具有不同功能作用的窄带振荡成分。这一观点得到了以下观察结果的支持：窄带振荡的相位通常与皮层兴奋性相关，并且可以与尖峰活动的时间和感觉诱发反应的保真度相关。因此，研究人员通常通过窄带滤波LFP来调谐到这些通道。或者，神经活动可能基本上是宽带的，并且由难以近似为振荡的瞬态非平稳节律组成。在这种观点中，广义系综的瞬时状态直接关系到当地人口的兴奋性，而不特别效忠于任何频带。为了测试这些选择之间的差异，我们询问两种性别绒猴的新皮质神经元的尖峰活动是否与窄频带内的LFP相位或宽带测量更好地一致。我们发现，宽带LFP波动的相位提供了一个更好的预测尖峰定时比在窄带滤波后的相位。这些结果挑战的观点，新皮层作为一个系统组成的窄带振荡器和支持的观点，神经活动波动本质上是宽带的。
Populations of cortical neurons generate rhythmic fluctuations in their ongoing spontaneous activity. These fluctuations can be seen in the local field potential (LFP), which reflects summed return currents from synaptic activity in the local population near a recording electrode. The LFP is spectrally broad, and many researchers view this breadth as containing many narrowband oscillatory components that may have distinct functional roles. This view is supported by the observation that the phase of narrowband oscillations is often correlated with cortical excitability and can relate to the timing of spiking activity and the fidelity of sensory evoked responses. Accordingly, researchers commonly tune in to these channels by narrowband filtering the LFP. Alternatively, neural activity may be fundamentally broadband and composed of transient, nonstationary rhythms that are difficult to approximate as oscillations. In this view, the instantaneous state of the broad ensemble relates directly to the excitability of the local population with no particular allegiance to any frequency band. To test between these alternatives, we asked whether the spiking activity of neocortical neurons in marmoset of either sex is better aligned with the phase of the LFP within narrow frequency bands or with a broadband measure. We find that the phase of broadband LFP fluctuations provides a better predictor of spike timing than the phase after filtering in narrow bands. These results challenge the view of the neocortex as a system composed of narrowband oscillators and supports a view in which neural activity fluctuations are intrinsically broadband.