Transcranial Focused Ultrasound Neuromodulation of Voluntary Movement-related Cortical Activity in Humans

Abstract

1Transcranial focused ultrasound (tFUS) is an emerging non-invasive brain 2 stimulation tool for safely and reversibly modulating brain circuits. The 3 effectiveness of tFUS on human brain has been demonstrated, but how tFUS 4 influences the human voluntary motor processing in the brain remains 5 unclear. We apply low-intensity tFUS to modulate the movement-related 6 cortical potential (MRCP) originating from human subjects practicing a 7 voluntary foot tapping task. 64-channel electroencephalograph (EEG) is 8 recorded concurrently and further used to reconstruct the brain source 9 activity specifically at the primary leg motor cortical area using the 10 electrophysiological source imaging (ESI). The ESI illustrates the ultrasound 11 modulated MRCP source dynamics with high spatiotemporal resolutions. 12The MRCP source is imaged and its source profile is further evaluated for 13 assessing the tFUS neuromodulatory effects on the voluntary MRCP. 14 Moreover, the effect of ultrasound pulse repetition frequency (UPRF) is 15 further assessed in modulating the MRCP. ESI results show that tFUS 16 significantly increases the MRCP source profile amplitude (MSPA) 17 comparing to a sham ultrasound condition, and further, a high UPRF 18 enhances the MSPA more than a low UPRF. This work provides the first 19 evidence of tFUS enhancing the human voluntary movement-related cortical 20 activity through excitatory modulation.21 485

Optically-generated focused ultrasound for noninvasive brain stimulation with ultrahigh precision

“…We estimate the theoretical maximum focal gain G max ≈ 280 for SOAP assuming uniform laser illumination with a frequency, a fnumber, a water attenuation coefficient, and a working distance of 15 MHz, 0.52, 2.2 × 10 −3 dB/(cm × MHz 2 ) and 2 mm, respectively. This theoretical maximum focal gain is 5-and 92-fold higher than that of a conventional PZTbased transducer with f N of 1 and 4, respectively 20,21,[31][32][33] . In summary, OFUS taking advantage of a high NA close to the limit enables a lateral resolution less than 100 µm at 15 MHz and a focal theoretical maximum pressure up to 92-fold higher compared to a PZT-based transducer at the same frequency.…”

“…g Theultrasound waveforms from 4 kinds of SOAPs with the same laser energy input. h The frequency spectra of ultrasound from 4 kinds of SOAPs of the NA in conventional PZT-based transducers 20,21,[31][32][33] . It is difficult for the single crystal piezoelectric material to reach a high NA due to the cracking in PZT-based single-element focused ultrasound transducers 34 .…”

Transcranial ultrasound stimulation to human middle temporal complex improves visual motion detection and modulates electrophysiological responses

“…1 In animal models, TUS can induce focal motor responses; 2 alter functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) responses 3 and electroencephalography (EEG) signals; 4 and, in non-human primates, cause changes in behavioural performance on complex cognitive tasks. 5 A small number of studies in humans have reported neuromodulatory effects of TUS in primary sensory [6][7][8][9] and motor [10][11][12][13][14] cortex and the thalamus. 15,16 No study has yet determined whether TUS is able to modulate human higher cognitive processes and their neural substrates in a spatially and temporally specific manner.…”

Ultrasound Neuromodulation and Correlation Change in the Rat Somatosensory Cortex

“…tFUS has been shown to elicit action potentials in various in vivo and in vitro studies in cell culture and brain slices (Muratore et al, 2009; Tyler et al, 2008) as well as across a variety of animals including worms (Kubanek et al, 2018), rodents (Juan et al, 2014; Mehić et al, 2014; Niu et al, 2018; Tufail et al, 2010; Younan et al, 2013; Yu et al, 2016), monkeys (Deffieux et al, 2013; Folloni et al, 2019), as well as humans (Hameroff et al, 2013; Lee et al, 2015; Legon et al, 2014; Liu et al, 2021; Verhagen et al, 2019; Yu, Liu, et al, 2021; Zhang et al, 2021). Effects from stimulation have been found on various many levels recordings including in multi-unit activity (MUA) (Tufail et al, 2010), local field potential (LFP) (Yuan et al, 2015), the blood oxygen level dependent (BOLD) signal (Verhagen et al, 2019), and EEG (Lee et al, 2015; Legon et al, 2014).…”