Department of Neuroscience, Brown University Providence, RI, USA ; Department of Neurology, Massachusetts General Hospital, Harvard Medical School Boston, MA, USA.
Front Integr Neurosci. 2013 Aug 12;7:58. doi: 10.3389/fnint.2013.00058. eCollection 2013.
Neocortical gamma (30-80 Hz) rhythms correlate with attention, movement and perception and are often disrupted in neurological and psychiatric disorders. Gamma primarily occurs during alert brain states characterized by the so-called "desynchronized" EEG. Is this because gamma rhythms are devoid of synchrony? In this review we take a historical approach to answering this question. Richard Caton and Adolf Beck were the first to report the rhythmic voltage fluctuations in the animal brain. They were limited by the poor amplification of their early galvanometers. Thus when they presented light or other stimuli, they observed a disappearance of the large resting oscillations. Several groups have since shown that visual stimuli lead to low amplitude gamma rhythms and that groups of neurons in the visual cortices fire together during individual gamma cycles. This synchronous firing can more strongly drive downstream neurons. We discuss how gamma-band synchrony can support ongoing communication between brain regions, and highlight an important fact: there is at least local neuronal synchrony during gamma rhythms. Thus, it is best to refer to the low amplitude, high frequency EEG as an "activated", not "desynchronized", EEG.
新皮层的伽马（30-80 Hz）节律与注意力、运动和感知相关，并且经常在神经和精神疾病中受到干扰。伽马主要发生在警觉状态的大脑中，表现为所谓的“去同步化”EEG。这是因为伽马节律缺乏同步性吗？在这篇综述中，我们采用历史的方法来回答这个问题。理查德·卡顿（Richard Caton）和阿道夫·贝克（Adolf Beck）是第一个报告动物大脑中节律性电压波动的人。他们受到早期检流计放大效果不佳的限制。因此，当他们呈现光或其他刺激时，他们观察到大量静止的振荡消失了。此后，有几个研究小组表明，视觉刺激会导致低幅度的伽马节律，并且视觉皮层中的神经元群组在单个伽马周期中一起发射。这种同步发射可以更强地驱动下游神经元。我们讨论了伽马波段同步如何支持大脑区域之间的持续通信，并强调了一个重要事实：在伽马节律期间存在至少局部的神经元同步性。因此，最好将低幅度、高频 EEG 称为“激活”的 EEG，而不是“去同步”的 EEG。
