Origins of 1/f2 scaling in the power spectrum of intracortical local field potential
Origins of 1/f2 scaling in the power spectrum of intracortical local field potential
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DOI：
10.1152/jn.00470.2011
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发表时间：
2012-02-01
影响因子：
2.5
通讯作者：
Fadiga, Luciano
中科院分区：
文献类型：
--
作者：
Baranauskas, Gytis;Maggiolini, Emma;Fadiga, Luciano
Baranaukas G，Maggiolini E，Vato A，Angozi G，Bonfanti A，Zambra G，Spinelli A，Fadiga L.皮层内局部场势功率谱的1/f(2)标度起源。神经生理学杂志107：984-994,2012。2011年11月16日首次出版；DOI：10.1152/jn.00470.2011。-已经注意到，皮质内局部场势(LFP)的功率谱通常标度为1/f(-2)。LFP被认为主要代表记录电极附近的突触电流和棘波等与放电相关的神经元活动，但在棘波功率中没有检测到1/f(2)标度。尽管组织过滤或上下状态对尖峰活动的调节可以解释观察到的LFP比例，但对于它是如何产生的还没有达成共识。我们通过同时记录麻醉大鼠躯体感觉皮层多个部位的LFP和单个神经元(“单个单位”)来解决这个问题。单单位数据揭示了高活动期的存在，推测对应于神经膜电位去极化时的“上”状态，以及不活动的时期，当膜电位接近静止时，假定为“下”状态。正如预期的那样，LFP功率比例为1/f(2)，但在尖峰活动的功率谱中没有发现这样的比例比例。我们的分析表明，LFP功率谱中的1/f(2)标度很大程度上是由上下能级之间的阶梯跃迁产生的。在这些转变期间，LFP信号的形状，而不是转变时间，对于获得观察到的标度是至关重要的。这些转变可能是由跨神经元的膜电位同步变化引起的。我们的结论是，LFP功率的1/f(2)比例表明LFP轨迹中存在阶梯状转变，并且几乎没有说明相关神经元放电的统计特性。
Baranauskas G, Maggiolini E, Vato A, Angotzi G, Bonfanti A, Zambra G, Spinelli A, Fadiga L. Origins of 1/f(2) scaling in the power spectrum of intracortical local field potential. J Neurophysiol 107: 984-994, 2012. First published November 16, 2011; doi:10.1152/jn.00470.2011.-It has been noted that the power spectrum of intracortical local field potential (LFP) often scales as 1/f(-2). It is thought that LFP mostly represents the spiking-related neuronal activity such as synaptic currents and spikes in the vicinity of the recording electrode, but no 1/f(2) scaling is detected in the spike power. Although tissue filtering or modulation of spiking activity by UP and DOWN states could account for the observed LFP scaling, there is no consensus as to how it arises. We addressed this question by recording simultaneously LFP and single neurons ("single units") from multiple sites in somatosensory cortex of anesthetized rats. Single-unit data revealed the presence of periods of high activity, presumably corresponding to the "UP" states when the neuronal membrane potential is depolarized, and periods of no activity, the putative "DOWN" states when the membrane potential is close to resting. As expected, the LFP power scaled as 1/f(2) but no such scaling was found in the power spectrum of spiking activity. Our analysis showed that 1/f(2) scaling in the LFP power spectrum was largely generated by the steplike transitions between UP and DOWN states. The shape of the LFP signal during these transitions, but not the transition timing, was crucial to obtain the observed scaling. These transitions were probably induced by synchronous changes in the membrane potential across neurons. We conclude that a 1/f(2) scaling in the LFP power indicates the presence of steplike transitions in the LFP trace and says little about the statistical properties of the associated neuronal firing.