Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
Comput Intell Neurosci. 2010;2010:393019. doi: 10.1155/2010/393019. Epub 2010 Feb 3.
Neurophysiologists have recently become interested in studying neuronal population activity through local field potential (LFP) recordings during experiments that also record the activity of single neurons. This experimental approach differs from early LFP studies because it uses high impedence electrodes that can also isolate single neuron activity. A possible complication for such studies is that the synaptic potentials and action potentials of the small subset of isolated neurons may contribute disproportionately to the LFP signal, biasing activity in the larger nearby neuronal population to appear synchronous and cotuned with these neurons. To address this problem, we used linear filtering techniques to remove features correlated with spike events from LFP recordings. This filtering procedure can be applied for well-isolated single units or multiunit activity. We illustrate the effects of this correction in simulation and on spike data recorded from primary auditory cortex. We find that local spiking activity can explain a significant portion of LFP power at most recording sites and demonstrate that removing the spike-correlated component can affect measurements of auditory tuning of the LFP.
神经生理学家最近开始通过在实验中记录局部场电位 (LFP) 来研究神经元群体活动，这些实验还记录单个神经元的活动。这种实验方法与早期的 LFP 研究不同，因为它使用高阻抗电极，也可以隔离单个神经元的活动。对于此类研究来说，一个可能的复杂情况是，一小部分被隔离的神经元的突触电位和动作电位可能不成比例地对 LFP 信号做出贡献，从而使附近较大的神经元群体的活动看起来与这些神经元同步且协调。为了解决这个问题，我们使用线性滤波技术从 LFP 记录中去除与尖峰事件相关的特征。这种滤波过程可应用于隔离良好的单个单位或多单位活动。我们在模拟和从初级听觉皮层记录的尖峰数据中说明了这种校正的效果。我们发现，局部尖峰活动可以解释大多数记录部位 LFP 功率的很大一部分，并且表明去除与尖峰相关的分量会影响 LFP 听觉调谐的测量。
