title: Effects of transcranial direct current stimulation on the functional coupling of the sensorimotor cortical network.
abstract: Transcranial direct current stimulation (tDCS) is well established-among the non-invasive brain stimulation techniques-as a method to modulate brain excitability. Polarity-dependent modulations of membrane potentials are detected after the application of anodal and cathodal stimulation, leading to changes in the electrical activity of the neurons. The main aim of the present study was to test the hypothesis that tDCS can affect-in a polarity-specific manner-the functional coupling of the sensorimotor areas during the eyes-open resting condition as revealed by total EEG coherence (i.e., coherence across the average of all combinations of the electrode pairs placed around the stimulation electrode). The changes in the total EEG coherence were evaluated pre-, during, and post-anodal and cathodal tDCS. While no differences were observed in the connectivity characteristics of the two pre-stimulation periods, a connectivity increase was observed in the alpha 2 band in the post-anodal tDCS with respect to pre-anodal and post-cathodal tDCS. The present study suggests that a specific approach based on the analyses of the functional coupling of EEG rhythms might enhance understanding of tDCS-induced effects on cortical connectivity. Moreover, this result suggests that anodal tDCS could possibly modify cortical connectivity more effectively with respect to cathodal tDCS.
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy. Electronic address: fabrizio.vecchio@uniroma1.it.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Vecchio
authors.affiliation: Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio, Fatebenefratelli, Brescia, Italy.
authors.forename: Maria Concetta
authors.initials: MC
authors.lastname: Pellicciari
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Miraglia
authors.affiliation: Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio, Fatebenefratelli, Brescia, Italy.
authors.forename: Debora
authors.initials: D
authors.lastname: Brignani
authors.affiliation: Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio, Fatebenefratelli, Brescia, Italy; Neuroscience Section, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Miniussi
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy; Institute of Neurology, Dept. Geriatrics, Neuroscience & Orthopedics, Catholic University.
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
mesh_terms: D000513:Alpha Rhythm / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D004569:Electroencephalography / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066191:Sensorimotor Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
keywords: Alpha band; EEG; Functional connectivity; Total coherence; tDCS