title: Cerebral cortex activation mapping upon electrical muscle stimulation by 32-channel time-domain functional near-infrared spectroscopy.
abstract: The application of different EMS current thresholds on muscle activates not only the muscle but also peripheral sensory axons that send proprioceptive and pain signals to the cerebral cortex. A 32-channel time-domain fNIRS instrument was employed to map regional cortical activities under varied EMS current intensities applied on the right wrist extensor muscle. Eight healthy volunteers underwent four EMS at different current thresholds based on their individual maximal tolerated intensity (MTI), i.e., 10 % < 50 % < 100 % < over 100 % MTI. Time courses of the absolute oxygenated and deoxygenated hemoglobin concentrations primarily over the bilateral sensorimotor cortical (SMC) regions were extrapolated, and cortical activation maps were determined by general linear model using the NIRS-SPM software. The stimulation-induced wrist extension paradigm significantly increased activation of the contralateral SMC region according to the EMS intensities, while the ipsilateral SMC region showed no significant changes. This could be due in part to a nociceptive response to the higher EMS current intensities and result also from increased sensorimotor integration in these cortical regions.
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, I-20133, Italy. rebecca.re@mail.polimi.it.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Re
authors.affiliation: Movement To Health (M2H) Laboratory, Euromov, Montpellier-1 University, Montpellier, France. makii.muthalib@univ-montp1.fr.|Movement Neuroscience Program, Queensland University of Technology, Brisbane, Australia. makii.muthalib@univ-montp1.fr.
authors.forename: Makii
authors.initials: M
authors.lastname: Muthalib
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, I-20133, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Contini
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, I-20133, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Zucchelli
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, I-20133, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Torricelli
authors.affiliation: Istituto di Fotonica e Nanotecnologie, CNR, Milan, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Spinelli
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, I-20133, Italy.|Department of Health Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Caffini
authors.affiliation: Department of Health Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Department of Health Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Quaresima
authors.affiliation: Movement To Health (M2H) Laboratory, Euromov, Montpellier-1 University, Montpellier, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Perrey
authors.affiliation: Movement Neuroscience Program, Queensland University of Technology, Brisbane, Australia.
authors.forename: Graham
authors.initials: G
authors.lastname: Kerr
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000378:metabolism / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D009132:Muscles / Q000294:innervation / Q000378:metabolism / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism; D010108:Oxyhemoglobins / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D014953:Wrist / Q000294:innervation / Q000502:physiology
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen