title: Acute effects of alcohol on stimulus-induced gamma oscillations in human primary visual and motor cortices.
abstract: Alcohol is a rich drug affecting both the γ-amino butyric acid (GABA) and glutamatergic neurotransmitter systems. Recent findings from both modeling and pharmacological manipulation have indicated a link between GABAergic activity and oscillations measured in the gamma frequency range (30-80 Hz), but there are no previous reports of alcohol's modulation of gamma-band activity measured by magnetoencephalography (MEG) or electroencephalography (EEG). In this single-blind, placebo-controlled crossover study, 16 participants completed two study days, on one day of which they consumed a dose of 0.8 g/kg alcohol, and on the other day a placebo. MEG recordings of brain activity were taken before and after beverage consumption, using visual grating and finger abduction paradigms known to induce gamma-band activity in the visual and motor cortices respectively. Time-frequency analyses of beamformer source reconstructions in the visual cortex showed that alcohol increased peak gamma amplitude and decreased peak frequency. For the motor task, alcohol increased gamma amplitude in the motor cortex. These data support the notion that gamma oscillations are dependent, in part, on the balance between excitation and inhibition. Disruption of this balance by alcohol, by increasing GABAergic inhibition at GABAA receptors and decreasing glutamatergic excitation at N-methyl-D-aspartic acid receptors, alters both the amplitude and frequency of gamma oscillations. The findings provide further insight into the neuropharmacological action of alcohol.
authors.affiliation: Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
authors.forename: Anne E
authors.identifier: 0000000306856734
authors.initials: AE
authors.lastname: Campbell
authors.affiliation: Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
authors.forename: Petroc
authors.initials: P
authors.lastname: Sumner
authors.affiliation: Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
authors.forename: Krish D
authors.initials: KD
authors.lastname: Singh
authors.affiliation: Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Muthukumaraswamy
mesh_terms: D000328:Adult; D002492:Central Nervous System Depressants / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004569:Electroencephalography; D004585:Electrooculography; D000431:Ethanol / Q000008:administration & dosage*; D005071:Evoked Potentials; D005260:Female; D005385:Fingers / Q000502:physiology; D065818:Gamma Rhythm / Q000187:drug effects*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009044:Motor Cortex / Q000187:drug effects* / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D012438:Saccades / Q000187:drug effects / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D016037:Single-Blind Method; D014793:Visual Cortex / Q000187:drug effects* / Q000502:physiology; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol