Neuronal mechanisms of cortical alpha oscillations in awake-behaving macaques.
Neuronal mechanisms of cortical alpha oscillations in awake-behaving macaques.
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DOI：
10.1523/jneurosci.2699-08.2008
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发表时间：
2008-10-01
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影响因子：
--
通讯作者：
Ding M
中科院分区：
文献类型：
--
作者：
Bollimunta A;Chen Y;Schroeder CE;Ding M
场电位振荡在10 Hz左右（α节律）被广泛注意到在视觉皮层，但其生理机制和意义知之甚少。体外研究表明，颗粒下层和颗粒上层的锥体神经元都是起搏器。对于行为主体的完整大脑，这些观察结果的普遍性是未知的。我们分析了自发局部场电位（LFPs）和多单位活动（MUA）记录线性阵列多电极从视觉区V2，V4和颞下（IT）皮质的两只猕猴在执行感觉辨别任务的层状配置文件。将电流源密度（CSD）分析与CSD-MUA相干性相结合，以识别皮质内α电流发生器及其α起搏潜力。通过格兰杰因果关系分析进一步描述了每个α电流发生器的作用。在V2和V4中，在所有层中都发现了α电流发生器，其中颗粒下发生器充当主要的局部起搏发生器。相反，在IT中，α电流发生器仅在颗粒上和颗粒下层中发现，颗粒上发生器作为主要的局部起搏发生器。在V2和V4的α活动的幅度与行为表现呈负相关，而相反的是真实的IT。因此，在IT的α节奏似乎不同于在较低级别的皮层，无论是在其潜在的生理机制和行为相关。这项工作可能有助于调和一些不同的发现和结论的视觉系统中的α波段振荡的功能意义。
Field potential oscillations at around 10 Hz (alpha rhythm) are widely noted in the visual cortices, but their physiological mechanisms and significance are poorly understood. In vitro studies have implicated pyramidal neurons in both infragranular and supragranular layers as pacemakers. The generality of these observations for the intact brain in the behaving subject is unknown. We analyzed laminar profiles of spontaneous Local Field Potentials (LFPs) and MultiUnit Activity (MUA) recorded with linear array multielectrodes from visual areas V2, V4 and inferotemporal (IT) cortex of two macaque monkeys during performance of a sensory discrimination task. Current source density (CSD) analysis was combined with CSD-MUA coherence to identify intracortical alpha current generators and their potential for alpha pacemaking. The role of each alpha current generator was further delineated by Granger causality analyses. In V2 and V4, alpha current generators were found in all layers, with the infragranular generator acting as primary local pacemaking generator. In contrast, in IT, alpha current generators were found only in supragranular and infragranular layers, with the supragranular generator acting as primary local pacemaking generator. The amplitude of alpha activity in V2 and V4 was negatively correlated with behavioral performance, while the opposite was true in IT. The alpha rhythm in IT thus appears to differ from that in the lower order cortices, both in terms of its underlying physiological mechanism and its behavioral correlates. This work may help to reconcile some of the diverse findings and conclusions on the functional significance of alpha band oscillations in the visual system.