Time course of the effects of low-intensity transcranial ultrasound on the excitability of ipsilateral and contralateral human primary motor cortex

NeuroImage

Jean-François Nankoo¹  Yanqiu Wang²  Anton Fomenko³  Ke Zeng⁴  Jian Zhang⁴  Andres M Lozano⁴  Robert Chen⁵  Xue Xia⁵ 

[1] Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada;Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada;Krembil Research Institute, University Health Network, Toronto, ON, Canada;Krembil Research Institute, University Health Network, Toronto, ON, Canada;School of Psychology, Shanghai University of Sport, Shanghai, China;

关键词: Transcranial ultrasound stimulation;    Transcranial magnetic stimulation;    Primary motor cortex;    Time course;    Transcallosal inhibition;   

DOI  :  

来源: DOAJ

【 摘 要 】

Low-intensity transcranial ultrasound stimulation (TUS) is a promising non-invasive brain stimulation technique that can modulate the excitability of cortical and deep brain structures with a high degree of focality. Previous human studies showed that TUS decreases motor cortex (M1) excitability measured by transcranial magnetic stimulation (TMS), but whether the effects appear beyond sonication and whether TUS affects the excitability of other interconnected cortical areas is not known. The time course of M1 TUS on ipsilateral and contralateral M1 excitability was investigated in 22 healthy human subjects via TMS-induced motor-evoked potentials. With sonication duration of 500 ms, we found suppression of M1 excitability from 10 ms before to 20 ms after the end of sonication, and the effects were stronger with blocked design compared to interleaved design. There was no significant effect on contralateral M1 excitability. Using ex-vivo measurements, we showed that the ultrasound transducer did not affect the magnitude or time course of the TMS-induced electromagnetic field. We conclude that the online-suppressive effects of TUS on ipsilateral M1 cortical excitability slightly outlast the sonication but did not produce long-lasting effects. The absence of contralateral effects may suggest that there are little tonic interhemispheric interactions in the resting state, or the intensity of TUS was too low to induce transcallosal inhibition.

【 授权许可】

Unknown