Finding synchrony in the desynchronized EEG: the history & interpretation of gamma rhythms

Frontiers in Integrative Neuroscience

卷:7

Sydney S. Cash¹  Omar J. Ahmed³ 

[1] Harvard Medical School;

[2] Brown University;

[3] Massachusetts General Hospital &

关键词: Desynchronization;    synchrony;    history of neuroscience;    Gamma rhythms;    activated EEG;   

DOI  :  10.3389/fnint.2013.00058

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown