Manipulation of Subcortical and Deep Cortical Activity in the Primate Brain Using Transcranial Focused Ultrasound Stimulation

SummaryThe causal role of an area within a neural network can be determined by interfering with its activity and measuring the impact. Many current reversible manipulation techniques have limitations preventing their focal application particularly in deep areas of the primate brain. Here we demonstrate a transcranial focused ultrasound stimulation (TUS) protocol that manipulates activity even in deep brain areas: a subcortical brain structure, the amygdala (experiment 1), and a deep cortical region, anterior cingulate cortex (ACC, experiment 2), in macaques. TUS neuromodulatory effects were measured by examining relationships between activity in each area and the rest of the brain using functional magnetic resonance imaging (fMRI). In control conditions without sonication, activity in a given area is related to activity in interconnected regions but such relationships are reduced after sonication. Dissociable and focal effects on neural activity could not be explained by auditory artefacts.

Download Full-text

Implication of Auditory Confounding in Interpreting Somatosensory and Motor Responses in Low-Intensity Transcranial Focused Ultrasound Stimulation

Journal of Neurophysiology ◽

10.1152/jn.00701.2020 ◽

2021 ◽

Author(s):

Christine Park ◽

Mengyue Chen ◽

Taewon Kim

Keyword(s):

Focused Ultrasound ◽

Auditory Pathway ◽

Localization Accuracy ◽

Motor Responses ◽

Non Invasive ◽

Low Intensity ◽

Ultrasound Stimulation ◽

Transcranial Focused Ultrasound ◽

Indirect Stimulation ◽

Stimulation Of

Low-intensity transcranial focused ultrasound (LI-tFUS) stimulation is a non-invasive neuromodulation tool that demonstrates high target localization accuracy and depth penetration. It has been shown to modulate activities in the primary motor and somatosensory cortex. Previous studies in animals and humans acknowledged the possibility of indirect stimulation of the peripheral auditory pathway that could confound the somatosensory and motor responses observed with LI-tFUS stimulation. Here, we discuss the implications and interpretations of auditory confounding in the context of neuromodulation.

Download Full-text

Safety of transcranial focused ultrasound stimulation: A systematic review of the state of knowledge from both human and animal studies

Brain Stimulation ◽

10.1016/j.brs.2019.07.024 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1367-1380 ◽

Cited By ~ 16

Author(s):

Cristina Pasquinelli ◽

Lars G. Hanson ◽

Hartwig R. Siebner ◽

Hyunjoo J. Lee ◽

Axel Thielscher

Keyword(s):

Systematic Review ◽

Animal Studies ◽

Focused Ultrasound ◽

The State ◽

Ultrasound Stimulation ◽

Transcranial Focused Ultrasound

Download Full-text

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

10.1101/2020.05.18.103176 ◽

2020 ◽

Author(s):

Kai Yu ◽

Chang Liu ◽

Xiaodan Niu ◽

Bin He

Keyword(s):

Voluntary Movement ◽

Focused Ultrasound ◽

Human Subjects ◽

Pulse Repetition Frequency ◽

Cortical Activity ◽

Source Imaging ◽

Source Profile ◽

Profile Amplitude ◽

The Brain ◽

Transcranial Focused Ultrasound

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

Download Full-text