The Institute of Neuroscience (IoNS) has the pleasure to invite you to the presentation entitled “Transcranial focused ultrasound brain stimulation of the somatosensory area induces offline changes in resting-state functional connectivity in humans” which will be given by Professor Seung-Schik Yoo (Harvard University) on Wednesday 28^th of September 2022 at 5:30 PM

Abstract:
The effects of transcranial focused ultrasound (tFUS) stimulation of the primary somatosensory cortex (S1) and its thalamic projection (i.e., ventral posterolateral nucleus; VPL) on off-line changes in resting-state functional connectivity (FC) were evaluated in healthy human volunteers. tFUS stimulation of the unilateral somatosensory circuits associated with the non-dominant hand elicited electroencephalogram (EEG) evoked potentials (EP) across all participants. FUS-induced EP (FEP), sharing similarities with somatosensory evoked potentials (SSEP) from median nerve stimulation, were observed from both brain hemispheres. Use of a 0.5-ms pulse duration (PD) sonication parameter, compared to the use of 1- and 2-ms PD, elicited more distinct EP peak features from the hemisphere ipsilateral to sonication. Several participants also reported hearing tones associated with tFUS stimulation, and a separate measurement of auditory evoked potentials (AEP) elicited by tonal stimulation (mimicking the same repetition frequency as the FUS stimulation), revealed that observed FEP were not likely to be confounded by the auditory sensation. The presence of off-line changes in FC associated with tFUS stimulation was assessed from acquiring multiple sessions of resting-state functional magnetic resonance imaging (rs-fMRI) before and after the sonication. Brain-wide FC analyses with respect to the sonicated brain regions showed that the effects of tFUS lasted for at least more than an hour, enhancing connectivity in the sensorimotor and network of sensory integration areas. Clinical neurological evaluations, EEG, and neuroanatomical MRI did not reveal any adverse or unintended effects of sonication. These results suggest the utility of tFUS stimulation in inducing long-term neuroplasticity.