Interhemispheric correlations of slow spontaneous neuronal fluctuations revealed in human sensory cortex.
Nat Neurosci
; 11(9): 1100-8, 2008 Sep.
Article
em En
| MEDLINE
| ID: mdl-19160509
ABSTRACT
Animal studies have shown robust electrophysiological activity in the sensory cortex in the absence of stimuli or tasks. Similarly, recent human functional magnetic resonance imaging (fMRI) revealed widespread, spontaneously emerging cortical fluctuations. However, it is unknown what neuronal dynamics underlie this spontaneous activity in the human brain. Here we studied this issue by combining bilateral single-unit, local field potentials (LFPs) and intracranial electrocorticography (ECoG) recordings in individuals undergoing clinical monitoring. We found slow (<0.1 Hz, following 1/f-like profiles) spontaneous fluctuations of neuronal activity with significant interhemispheric correlations. These fluctuations were evident mainly in neuronal firing rates and in gamma (40-100 Hz) LFP power modulations. Notably, the interhemispheric correlations were enhanced during rapid eye movement and stage 2 sleep. Multiple intracranial ECoG recordings revealed clear selectivity for functional networks in the spontaneous gamma LFP power modulations. Our results point to slow spontaneous modulations in firing rate and gamma LFP as the likely correlates of spontaneous fMRI fluctuations in the human sensory cortex.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Mapeamento Encefálico
/
Potenciais de Ação
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Córtex Cerebral
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Potenciais Evocados
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Lateralidade Funcional
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Neurônios
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Nat Neurosci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Israel