High-Resolution Transcranial Electrical Simulation for Living Mice Based on Magneto-Acoustic Effect

Abstract

Transcranial electrical stimulation is an important neuromodulation tool, which has been widely applied in the cognitive sciences and in the treatment of neurological and psychiatric diseases. In this work, a novel non-invasive method of transcranial electrical stimulation with high-resolution transcranial magneto-acoustic stimulation (TMAS) method has been tested experimentally in living mice for the first time. It can achieve spatial resolution of 2 mm in the cortex and even in the deep brain regions. The induced electrical field of TMAS was simulated and measured using a test sample. Then, an animal experimental system was built, and the healthy as well as Parkinson's disease (PD) mice were simulated by TMAS in vivo. To investigate the effect of transcranial ultrasound stimulation (TUS) at the same time as TMAS, a TUS group was added in the experiments and its results compared with those of the TMAS group. The results not only demonstrate the high-resolution ability and safety of TMAS, but also show that both TMAS and TUS improved the synaptic plasticity of the PD mice and might improve the spatial learning and memory ability of the healthy mice and the PD mice, although the improvement performance of the TMAS group was superior to that of the TUS-group. Based on the in vivo TMAS studies, we propose that TMAS functions as a dual-mode stimulation combining the electric field of the magnetoacoustic effect and the mechanical force of TUS. Our results also provide an explanation of the mechanism of TMAS. This research suggests that future use of US stimulation in magnetic resonance imaging (MRI)-guided studies should involve careful consideration of the induced magneto-acoustic electrical field caused by the static magnetic field of MRI.

Transcranial Magneto-Acoustic Stimulation Attenuates Synaptic Plasticity Impairment through the Activation of Piezo1 in Alzheimer’s Disease Mouse Model

“…We have demonstrated that TMAS can be used to generate an electric field in a conductive medium upright to the orientation of the magnetic and sound fields and that the electric field coverage is extremely consistent with that of the acoustic field in our previous work [ 23 ]. TMAS integrates a magneto-acoustic electric field and the mechanical force of TUS [ 22 ]. The mechanical force of TUS may alter ion channels so that electric field stimulation has a much stronger effect.…”

“…S7 and S8 ). In the effective electrical stimulation results of the in vivo study, the electric fields with intensities ranging from 10 to 338 mV/m [ 22 , 63 – 65 ]. The strengths of the acoustic (0.3 MPa) and electric fields (36 mV/m) produced in our study are both in the range of the effective stimulus parameters.…”

“…The conductive particles inside the brain tissue driven by ultrasound waves can stimulate the generation of electric field current in the magnetic field. The correlation between the electric field and the velocity of the particles enables manipulation of the effect of TMAS on the basis of Faraday’s law [ 22 , 23 ]. TMAS can achieve high spatial resolution at low millimeter level deep in the brain by using the high focusing property of ultrasound [ 22 ].…”

“…The correlation between the electric field and the velocity of the particles enables manipulation of the effect of TMAS on the basis of Faraday’s law [ 22 , 23 ]. TMAS can achieve high spatial resolution at low millimeter level deep in the brain by using the high focusing property of ultrasound [ 22 ]. Compared with transcranial magnetic stimulation (TMS), TMAS can obtain better localization and target stimulation of functional brain areas while ensuring stimulation depth [ 23 , 24 ], which has important research value and application prospect especially in the field of functional brain partitioning and deep transcranial stimulation with higher requirements for stimulation targeting.…”

Effect of Low Intensity Transcranial Ultrasound Stimulation on Neuromodulation in Animals and Humans: An Updated Systematic Review

“…Behavioral outcome associated with immunofluorescence technique measurements indicated that after 4 days of LI-TUS at M1 with 0.76 W/cm 2 ( I SPPA) in PD mice showed an increase of c-Fos positive cells in M1 as well as superior behavioral performance compared to the sham control group (Zhou et al, 2019a). When the substantia nigra (SN) was stimulated (Zhou et al, 2019b), the stimulated healthy mice did not exhibit significantly different behavior compared to the control mice. However, stimulation of SN in PD mice did induce significant improvement in spatial related forms of motor behavior performance than the control group.…”