Stochastic generation of gamma-band activity in primary visual cortex of awake and anesthetized monkeys

Dajun Xing, Yutai Shen, Samuel Burns, Chun I. Yeh, Robert Shapley, Wu Li

Research output: Contribution to journalArticle

Abstract

Oscillatory neural activity within the gamma band (25-90 Hz) is generally thought to be able to provide a timing signal for harmonizing neural computations across different brain regions. Using time-frequency analyses of the dynamics of gamma-band activity in the local field potentials recorded from monkey primary visual cortex, we found identical temporal characteristics of gamma activity in both awake and anesthetized brain states, including large variability of peak frequency, brief oscillatory epochs (<100 ms on average), and stochastic statistics of the incidence and duration of oscillatory events. These findings indicate that gamma-band activity is temporally unstructured and is inherently a stochastic signal generated by neural networks. This idea was corroborated further by our neuralnetwork simulations. Our results suggest that gamma-band activity is too random to serve as a clock signal for synchronizing neuronal responses in awake as in anesthetized monkeys. Instead, gamma-band activity is more likely to be filtered neuronal network noise. Its mean frequency changes with global state and is reduced under anesthesia.

Original languageEnglish (US)
Pages (from-to)13873-13880
Number of pages8
JournalJournal of Neuroscience
Volume32
Issue number40
DOIs
StatePublished - Oct 3 2012

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ASJC Scopus subject areas

  • Neuroscience(all)

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