Transcranial ultrasound stimulation of the human motor cortex

Abstract

Summary It has been 40 years since the report of long-term synaptic plasticity on the rodent brain. Transcranial ultrasound stimulation (TUS) shows advantages in spatial resolution and penetration depth when compared with electrical or magnetic stimulation. The repetitive TUS (rTUS) can induce cortical excitability alteration on animals, and persistent aftereffects were observed. However, the effects of rTUS on synaptic plasticity in humans remain unelucidated. In the current study, we applied a 15-min rTUS protocol to stimulate left primary motor cortex (l-M1) in 24 male healthy participants. The single-pulsed transcranial magnetic stimulation-evoked motor evoked potential and Stop-signal task was applied to measure the rTUS aftereffects. Here, we report that conditioning the human motor cortex using rTUS may produce long-lasting and statistically significant effects on motor cortex excitability as well as motor behavior, without harmful side effects observed. These findings suggest a considerable potential of rTUS in cortical plasticity modulation and clinical intervention for impulsivity-related disorders.

Transcranial focused ultrasound induces sustained synaptic plasticity in rat hippocampus

“…Primary rat cortical neuron cultures have shown neuronal excitability changes in response to 40 s of 5 Hz pulsed ultrasound stimulation, suggesting the presence of plasticity-like mechanism [26]. In human subjects, 15 min of pulsed ultrasound stimulation with 5% duty cycle and 100 Hz pulse repetition frequency (PRF) at the motor cortex significantly potentiates amplitude of motor evoked potentials, lasting longer than 30 min [27]. These are early evidences of ultrasound-induced neuroplasticity.…”

A causal role of anterior prefrontal-putamen circuit for response inhibition revealed by transcranial ultrasound stimulation in humans

“…TUS can noninvasively stimulate the deep brain structures with high spatial accuracy of a few millimeters (Cain et al, 2021;Darmani et al, 2022;Folloni et al, 2019;Fomenko et al, 2018;Fouragnan et al, 2019;Kubanek et al, 2020;Legon et al, 2014;Pasquinelli et al, 2019). Previous studies have reported that TUS can induce short-or long-term suppression/enhancement of the activity depending on stimulation protocols (Fomenko et al, 2020;Legon et al, 2018;Verhagen et al, 2019;Zeng et al, 2022;Zhang et al, 2021). We first confirmed the sustained suppression of cortical activity after TUS in the human primary motor cortex (M1) by measuring motor-evoked potential (MEP) with transcranial magnetic stimulation (TMS) (stage 1; Figure 1A).…”

Radiomics-Informed Modeling for Transcranial Ultrasound Stimulation: Age Matters

“…Interestingly, pre-treatment transcranial model could be employed as a turnkey solution for optimizing the parameters for treatment targets and, meanwhile, examining the biophysical mechanisms of TUS at individual level. Previous studies focused on investigating the spatial distribution of TUS effect are based on the magnetic resonance imaging (MRI) or computed tomography scans of young adults with an average head size (Koh et al, 2021 ; Zhang et al, 2021 ). However, this standard model has limited power to represent the distribution of TUS-induced effects in the individuals with various skull and brain morphology.…”