title: Dynamic aftereffects in supplementary motor network following inhibitory transcranial magnetic stimulation protocols.
abstract: The supplementary motor area (SMA) is a key node of the motor network. Inhibitory repetitive transcranial magnetic stimulation (rTMS) of the SMA can potentially improve movement disorders. However, the aftereffects of inhibitory rTMS on brain function remain largely unknown. Using a single-blind, crossover within-subject design, we investigated the role of aftereffects with two inhibitory rTMS protocols [1800 pulses of either 1-Hz repetitive stimulation or continuous theta burst stimulation (cTBS)] on the left SMA. A total of 19 healthy volunteers participated in the rTMS sessions on 2 separate days. Firstly, short-term aftereffects were estimated at three levels (functional connectivity, local activity, and network properties) by comparing the resting-state functional magnetic resonance imaging datasets (9min) acquired before and after each rTMS session. Local activity and network properties were not significantly altered by either protocol. Functional connectivity within the SMA network was increased (in the left paracentral gyrus) by 1-Hz stimulation and decreased (in the left inferior frontal gyrus and SMA/middle cingulate cortex) by cTBS. The subsequent three-way analysis of variance (site×time×protocol) did not show a significant interaction effect or "protocol" main effect, suggesting that the two protocols share an underlying mechanism. Secondly, sliding-window analysis was used to evaluate the dynamic features of aftereffects in the ~29min after the end of stimulation. Aftereffects were maintained for a maximum of 9.8 and 6.6min after the 1-Hz and cTBS protocols, respectively. In summary, this study revealed topographical and temporal aftereffects in the SMA network following inhibitory rTMS protocols, providing valuable information for their application in future neuroscience and clinical studies.
authors.affiliation: Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei 230000, China; Collaborative Innovation Centre of Neuropsychiatric Disorder and Mental Health, Anhui Province 230000, China.
authors.forename: Gong-Jun
authors.initials: GJ
authors.lastname: Ji
authors.affiliation: Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei 230000, China.
authors.forename: Fengqiong
authors.initials: F
authors.lastname: Yu
authors.affiliation: Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liao
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230000, China; Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei 230000, China; Collaborative Innovation Centre of Neuropsychiatric Disorder and Mental Health, Anhui Province 230000, China. Electronic address: wangkai1964@126.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
mesh_terms: D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D038361:Neuronavigation / Q000379:methods; D016037:Single-Blind Method; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: Dynamic; Healthy subject; Resting-state; Theta burst stimulation; Transcranial magnetic stimulation; functional MRI