title: Direct current stimulation over the human sensorimotor cortex modulates the brain's hemodynamic response to tactile stimulation.
abstract: Tactile stimuli produce afferent signals that activate specific regions of the cerebral cortex. Noninvasive transcranial direct current stimulation (tDCS) effectively modulates cortical excitability. We therefore hypothesised that a single session of tDCS targeting the sensory cortices would alter the cortical response to tactile stimuli. This hypothesis was tested with a block-design functional magnetic resonance imaging protocol designed to quantify the blood oxygen level-dependent response to controlled sinusoidal pressure stimulation applied to the right foot sole, as compared with rest, in 16 healthy young adults. Following sham tDCS, right foot sole stimulation was associated with activation bilaterally within the precentral cortex, postcentral cortex, middle and superior frontal gyri, temporal lobe (subgyral) and cingulate gyrus. Activation was also observed in the left insula, middle temporal lobe, superior parietal lobule, supramarginal gyrus and thalamus, as well as the right inferior parietal lobule and claustrum (false discovery rate corrected, P < 0.05). To explore the regional effects of tDCS, brain regions related to somatosensory processing, and cortical areas underneath each tDCS electrode, were chosen as regions of interest. Real tDCS, as compared with sham tDCS, increased the percent signal change associated with foot stimulation relative to rest in the left posterior paracentral lobule. These results indicate that tDCS acutely modulated the cortical responsiveness to controlled foot pressure stimuli in healthy adults. Further study is warranted, in both healthy individuals and patients with sensory impairments, to link tDCS-induced modulation of the cortical response to tactile stimuli with changes in somatosensory perception.
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.
authors.forename: Junhong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Berenson-Allen Center for Noninvasive Brain Stimulation and Cognitive Neurology Unit, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fried
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.|Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.|College of Engineering, Peking University, Beijing, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing, 100871, China.|College of Engineering, Peking University, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Berenson-Allen Center for Noninvasive Brain Stimulation and Cognitive Neurology Unit, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Berenson-Allen Center for Noninvasive Brain Stimulation and Cognitive Neurology Unit, Beth Israel Deaconess Medical Center, Boston, MA, USA.|Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.
authors.forename: Brad
authors.initials: B
authors.lastname: Manor
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D005528:Foot; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010812:Physical Stimulation; D066191:Sensorimotor Cortex / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: sensorimotor cortex; tDCS; tactile stimuli