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

Transcranial magneto-acoustic stimulation enhances motor function and modulates cortical excitability of motor cortex in a Parkinson's disease mouse model

Parkinson's disease (PD) is a neurodegenerative disorder characterized primarily by motor dysfunction. Transcranial magneto-acoustic stimulation (TMAS), an emerging non-invasive brain neuromodulation technology, is increasingly being applied in the treatment of brain diseases. However, the effects of TMAS on PD are unknown, which is not well studied. Here, we utilized TMAS on PD model mice induced by MPTP to investigate the underlying mechanism of therapy. Our study found that TMAS improved the behavioral performance of PD model mice, enhancing the motor function and motivation for movement. Besides, it inhibited the increased beta oscillations in the motor cortex, while also reducing gamma oscillations. Moreover, the abnormally exaggerated beta-broad gamma phase amplitude coupling (PAC) was decreased after TMAS, and there was a significant negative correlation between PAC and both distance traveled and mean speed during the open filed test. Additionally, the ongoing stimulation could provide neuroprotection, implying that TMAS could ameliorate the loss of dopaminergic neurons, with no damage observed in the brain tissue of mice. Our findings suggest that TMAS could provide a non-invasive tool for the treatment of Parkinson's disease and beta-broad gamma phase amplitude coupling could be employed as a biomarker for PD.

Advancing Neuroscience and Therapy: Insights into Genetic and Non-Genetic Neuromodulation Approaches

Neuromodulation stands as a cutting-edge approach in the fields of neuroscience and therapeutic intervention typically involving the regulation of neural activity through physical and chemical stimuli. The purpose of this review is to provide an overview and evaluation of different neuromodulation techniques, anticipating a clearer understanding of the future developmental trajectories and the challenges faced within the domain of neuromodulation that can be achieved. This review categorizes neuromodulation techniques into genetic neuromodulation methods (including optogenetics, chemogenetics, sonogenetics, and magnetogenetics) and non-genetic neuromodulation methods (including deep brain stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, transcranial ultrasound stimulation, photobiomodulation therapy, infrared neuromodulation, electromagnetic stimulation, sensory stimulation therapy, and multi-physical-factor stimulation techniques). By systematically evaluating the principles, mechanisms, advantages, limitations, and efficacy in modulating neuronal activity and the potential applications in interventions of neurological disorders of these neuromodulation techniques, a comprehensive picture is gradually emerging regarding the advantages and challenges of neuromodulation techniques, their developmental trajectory, and their potential clinical applications. This review highlights significant advancements in applying these techniques to treat neurological and psychiatric disorders. Genetic methods, such as sonogenetics and magnetogenetics, have demonstrated high specificity and temporal precision in targeting neuronal populations, while non-genetic methods, such as transcranial magnetic stimulation and photobiomodulation therapy, offer noninvasive and versatile clinical intervention options. The transformative potential of these neuromodulation techniques in neuroscience research and clinical practice is underscored, emphasizing the need for integration and innovation in technologies, the optimization of delivery methods, the improvement of mediums, and the evaluation of toxicity to fully harness their therapeutic potential.

Vibrotactile stimulation at 40 Hz inhibits Aβ-induced changes in SH-SY5Y, BV2 cells, and pericytes

Alzheimer's disease (AD) poses a major societal challenge, yet no definitive cure exists. Noninvasive brain stimulation methods, such as transcranial magnetic stimulation and transcranial direct current stimulation, have shown promise in alleviating cognitive symptoms associated with neurodegenerative disorders. This study investigated the effects of 40 Hz vibrotactile stimulation on AD-related cellular responses using SH-SY5Y neuroblastoma cells, primary human brain pericytes, and BV2 microglia. SH-SY5Y cells and brain pericytes treated with oligomeric beta-amyloid (Aβ) underwent 40 Hz vibrational stimulation for varying durations. Cell viability was determined via the CCK-8 assay, while intracellular calcium levels in pericytes were assessed. Protein expression was measured using western blotting, and gene expression was quantified via a real-time quantitative polymerase chain reaction. Detailed vibrational parameters were employed to ensure precise stimulation. Notably, 40 Hz vibrotactile stimulation improved cell viability in Aβ-exposed SH-SY5Y cells, reduced intracellular calcium ion (Ca2+) levels in Aβ-treated pericytes, activated autophagy, and mitigated tau hyperphosphorylation in SH-SY5Y cells. Additionally, it exhibited anti-neuroinflammatory properties in BV2 microglia. These findings highlight the potential of 40 Hz vibrotactile stimulation as a therapeutic strategy for AD.

Ultrasound Stimulation Modulates Microglia M1/M2 Polarization and Affects Hippocampal Proteomic Changes in a Mouse Model of Alzheimer's Disease

BACKGROUND

The effectiveness of ultrasound stimulation in treating Alzheimer's disease (AD) has been reported in previous studies, but the underlying mechanisms remain unclear. This study investigated the effects of ultrasound stimulation on the proportion and function of microglia of different phenotypes, as well as on the levels of inflammatory factors. Additionally, it revealed the alterations in proteomic molecules in the mouse hippocampus following ultrasound stimulation treatment, aiming to uncover potential new molecular mechanisms.

METHODS

Ultrasound stimulation was used to stimulate the hippocampus for 30 min per day for 5 days in the ultrasound stimulation-treated group. Amyloid plaque deposition was measured using immunofluorescence staining. M1 and M2 type microglia were labeled using immunofluorescent double staining, and the ratio was calculated. The levels of Aβ42, IL-10, and TNF-α were determined using ELISA kits. The quantitative proteomics method was employed to explore molecular changes in hippocampal proteins.

RESULTS

Ultrasound stimulation treatment reduced the average fluorescence intensity of amyloid plaques and the concentration of Aβ42. Compared to the AD group, ultrasound stimulation resulted in a 14% reduction in the proportion of M1 microglia and a 12% increase in the proportion of M2 microglia. The concentration of the anti-inflammatory factor IL-10 was significantly increased in the ultrasound stimulation-treated group. Proteomics analysis revealed 753 differentially expressed proteins between the ultrasound stimulation-treated and AD groups, with most being enriched in the oxidative phosphorylation pathway of mitochondria. Additionally, the activity of cytochrome c oxidase, involved in oxidative phosphorylation, was increased after ultrasound stimulation treatment.

CONCLUSIONS

Ultrasound stimulation affects microglial polarization, reduces amyloid plaque load, and enhances levels of anti-inflammatory factors in APP/PS1 mice. Proteomics analysis reveals molecular changes in hippocampal proteins after ultrasound stimulation treatment. The mechanism behind ultrasound stimulation-induced modulation of microglial polarization may be related to changes in mitochondrial oxidative phosphorylation.

A simulation study of transcranial magnetoacoustic stimulation of the basal ganglia thalamic neural network to improve pathological beta oscillations in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disease. Transcranial magnetoacoustic stimulation (TMAS) is a new therapy that combines a transcranial focused acoustic pressure field with a magnetic field to excite or inhibit neurons in targeted area, which suppresses the abnormally elevated beta band amplitude in PD states, with high spatial resolution and non-invasively.

OBJECTIVE

To study the effective stimulation parameters of TMAS mononuclear and multinuclear stimulation for the treatment of PD with reduced beta band energy, improved abnormal synchronization, and no thermal damage.

METHODS

The TMAS model is constructed based on the volunteer's computed tomography, 128 arrays of phase-controlled transducers, and permanent magnets. A basal ganglia-thalamic (BG-Th) neural network model of the PD state was constructed on the basis of the Izhikevich model and the acoustic model. An ultrasound stimulation neuron model is constructed based on the Hodgkin-Huxley model. Numerical simulations of transcranial focused acoustic pressure field, temperature field and induced electric field at single and dual targets were performed using the locations of STN, GPi, and GPe in the human brain as the main stimulation target areas. And the acoustic and electric parameters at the focus were extracted to stimulate mononuclear and multinuclear in the BG-Th neural network.

RESULTS

When the stimulating effect of ultrasound is ignored, TMAS-STN simultaneously inhibits the beta-band amplitude of the GPi nucleus, whereas TMAS-GPi fails to simultaneously have an inhibitory effect on the STN. TMAS-STN&GPi can reduce the beta band amplitude. TMAS-STN&GPi&GPe suppressed the PD pathologic beta band amplitude of each nucleus to a greater extent. When considering the stimulatory effect of ultrasound, lower sound pressures of ultrasound do not affect the neuronal firing state, but higher sound pressures may promote or inhibit the stimulatory effect of induced currents.

CONCLUSIONS

At 9 T static magnetic field, 0.5-1.5 MPa and 1.5-2.0 MPa ultrasound had synergistic effects on individual STN and GPi neurons. TMAS multinuclear stimulation with appropriate ultrasound intensity was the most effective in suppressing the amplitude of pathological beta oscillations in PD and may be clinically useful.

Repetitive Transcranial Magnetic Stimulation (rTMS) Improves Cognitive Impairment and Intestinal Microecological Dysfunction Induced by High-Fat Diet in Rats

Consuming a high-fat diet (HFD) is widely recognized to cause obesity and result in chronic brain inflammation that impairs cognitive function. Repetitive transcranial magnetic stimulation (rTMS) has shown effectiveness in both weight loss and cognitive improvement, although the exact mechanism is still unknown. Our study examined the effects of rTMS on the brain and intestinal microecological dysfunction. rTMS successfully reduced cognitive decline caused by an HFD in behavioral assessments involving the Y maze and novel object recognition. This was accompanied by an increase in the number of new neurons and the transcription level of genes related to synaptic plasticity (spindlin 1, synaptophysin, and postsynaptic protein-95) in the hippocampus. It was reached that rTMS decreased the release of high mobility group box 1, activation of microglia, and inflammation in the brains of HFD rats. rTMS also reduced hypothalamic hypocretin levels and improved peripheral blood lipid metabolism. In addition, rTMS recovered the HFD-induced gut microbiome imbalances, metabolic disorders, and, in particular, reduced levels of the microvirus. Our research emphasized that rTMS enhanced cognitive abilities, resulting in positive impacts on brain inflammation, neurodegeneration, and the microbiota in the gut, indicating the potential connection between the brain and gut, proposing that rTMS could be a new approach to addressing cognitive deficits linked to obesity.

Study on Improving the Modulatory Effect of Rhythmic Oscillations by Transcranial Magneto-Acoustic Stimulation

In hippocampus, synaptic plasticity and rhythmic oscillations reflect the cytological basis and the intermediate level of cognition, respectively. Transcranial ultrasound stimulation (TUS) has demonstrated the ability to elicit changes in neural response. However, the modulatory effect of TUS on synaptic plasticity and rhythmic oscillations was insufficient in the present studies, which may be attributed to the fact that TUS acts mainly through mechanical forces. To enhance the modulatory effect on synaptic plasticity and rhythmic oscillations, transcranial magneto-acoustic stimulation (TMAS) which induced a coupled electric field together with TUS's ultrasound field was applied. The modulatory effect of TMAS and TUS with a pulse repetition frequency of 100 Hz were compared. TMAS/TUS were performed on C57 mice for 7 days at two different ultrasound intensities (3 W/cm2 and 5 W/cm [Formula: see text]. Behavioral tests, long-term potential (LTP) and local field potentials in vivo were performed to evaluate TUS/TMAS modulatory effect on cognition, synaptic plasticity and rhythmic oscillations. Protein expression based on western blotting were used to investigate the under- lying mechanisms of these beneficial effects. At 5 W/cm2, TMAS-induced LTP were 113.4% compared to the sham group and 110.5% compared to TUS. Moreover, the relative power of high gamma oscillations (50-100Hz) in the TMAS group ( 1.060±0.155 %) was markedly higher than that in the TUS group ( 0.560±0.114 %) and sham group ( 0.570±0.088 %). TMAS significantly enhanced the synchronization of theta and gamma oscillations as well as theta-gamma cross-frequency coupling. Whereas, TUS did not show relative enhancements. TMAS provides enhanced effect for modulating the synaptic plasticity and rhythmic oscillations in hippocampus.

Study on the Role of Physical Fields in TMAS to Modulate Synaptic Plasticity in Mice

OBJECTIVE

Transcranial magneto-acoustic stimulation (TMAS) is a composite technique combining static magnetic and coupled electric fields with transcranial ultrasound stimulation (TUS) and has shown advantages in neuromodulation. However, the role of these physical fields in neuromodulation is unclear. Synaptic plasticity is the cellular basis for learning and memory. In this paper, we varied the intensity of static magnetic, electric and ultrasonic fields respectively to investigate the modulation of synaptic plasticity by these physical fields.

METHODS

There are control, static magnetic field (0.1 T/0.2 T), TUS (0.15/0.3 MPa), and TMAS (0.15 MPa + 0.2 V/m, 0.3 MPa + 0.2 V/m, 0.3 MPa + 0.4 V/m) groups. Hippocampal areas were stimulated at 5 min daily for 7 days and in vivo electrophysiological experiments were performed.

RESULTS

TMAS induced greater LTP, LTD, and paired-pulse ratio (PPR) than TUS, reflecting that TMAS has a more significant modulation in both long- and short- term synaptic plasticity. In TMAS, a doubling of the electric field amplitude increases LTP, LTD and PPR to a greater extent than a doubling of the acoustic pressure. Increasing the static magnetic field intensity has no significant effect on the modulation of synaptic plasticity.

CONCLUSION

This paper argues that electric fields should be the main reason for the difference in modulation between TMAS and TUS and that changing the amplitude of the electric field affected the modulation of TMAS more than changing the acoustic pressure.

SIGNIFICANCE

This study elucidates the roles of the physical fields in TMAS and provides a parameterisation way to guide TMAS applications based on the dominant roles of the physical fields.

Pharmacological Activation of Piezo1 Channels Enhances Astrocyte-Neuron Communication via NMDA Receptors in the Murine Neocortex

The Piezo1 mechanosensitive ion channel is abundant on several elements of the central nervous system including astrocytes. It has been already demonstrated that activation of these channels is able to elicit calcium waves on astrocytes, which contributes to the release of gliotransmitters. Astrocyte- and N-methyl-D-aspartate (NMDA) receptor-dependent slow inward currents (SICs) are hallmarks of astrocyte-neuron communication. These currents are triggered by glutamate released as gliotransmitter, which in turn activates neuronal NMDA receptors responsible for this inward current having slower kinetics than any synaptic events. In this project, we aimed to investigate whether Piezo1 activation and inhibition is able to alter spontaneous SIC activity of murine neocortical pyramidal neurons. When the Piezo1 opener Yoda1 was applied, the SIC frequency and the charge transfer by these events in a minute time was significantly increased. These changes were prevented by treating the preparations with the NMDA receptor inhibitor D-AP5. Furthermore, Yoda1 did not alter the spontaneous EPSC frequency and amplitude when SICs were absent. The Piezo1 inhibitor Dooku1 effectively reverted the actions of Yoda1 and decreased the rise time of SICs when applied alone. In conclusion, activation of Piezo1 channels is able to alter astrocyte-neuron communication. Via enhancement of SIC activity, astrocytic Piezo1 channels have the capacity to determine neuronal excitability.

Dynamical modulation of hypersynchronous seizure onset with transcranial magneto-acoustic stimulation in a hippocampal computational model

Hypersynchronous (HYP) seizure onset is one of the frequently observed seizure-onset patterns in temporal lobe epileptic animals and patients, often accompanied by hippocampal sclerosis. However, the exact mechanisms and ion dynamics of the transition to HYP seizures remain unclear. Transcranial magneto-acoustic stimulation (TMAS) has recently been proposed as a novel non-invasive brain therapy method to modulate neurological disorders. Therefore, we propose a biophysical computational hippocampal network model to explore the evolution of HYP seizure caused by changes in crucial physiological parameters and design an effective TMAS strategy to modulate HYP seizure onset. We find that the cooperative effects of abnormal glial uptake strength of potassium and excessive bath potassium concentration could produce multiple discharge patterns and result in transitions from the normal state to the HYP seizure state and ultimately to the depolarization block state. Moreover, we find that the pyramidal neuron and the PV+ interneuron in HYP seizure-onset state exhibit saddle-node-on-invariant-circle/saddle homoclinic (SH) and saddle-node/SH at onset/offset bifurcation pairs, respectively. Furthermore, the response of neuronal activities to TMAS of different ultrasonic waveforms revealed that lower sine wave stimulation can increase the latency of HYP seizures and even completely suppress seizures. More importantly, we propose an ultrasonic parameter area that not only effectively regulates epileptic rhythms but also is within the safety limits of ultrasound neuromodulation therapy. Our results may offer a more comprehensive understanding of the mechanisms of HYP seizure and provide a theoretical basis for the application of TMAS in treating specific types of seizures.

Transcranial magneto-acoustic stimulation improves spatial memory and modulates hippocampal neural oscillations in a mouse model of Alzheimer's disease

Introduction

In our study, we applied transcranial magneto-acoustic stimulation (TMAS), a technique based on focused ultrasound stimulation within a static magnetic field, in the APP/PS1 mouse model of Alzheimer's disease (AD) to explore the feasibility of TMAS on improving AD related spatial memory deficits and abnormal neural oscillations.

Methods

The mice treated with TMAS once daily for 21 days. We recorded local field potential signals in the hippocampal CA1 region of the mice after TMAS treatment with in-vivo electrophysiology and evaluated the neural rehabilitative effect of TMAS with sharp-wave ripple (SWR), gamma oscillations during SWRs, and phase-amplitude coupling (PAC). The spatial memory function of the mice was examined by the Morris water maze (MWM) task.

Results

We found that TMAS improved the performance of MWM related spatial cognitive functions compared with AD group. Furthermore, our results implied that TMAS alleviated abnormalities in hippocampal SWRs, increased slow gamma power during SWRs, and promoted theta-slow gamma phase-amplitude coupling. These findings suggest that TMAS could have a positive influence on spatial memory through the modulation of neural oscillations.

Discussion

This work emphasizes the potential of TMAS to serve as a non-invasive method for Alzheimer's disease rehabilitation and promote the application of TMAS for the treatment of more neurological and brain aging diseases in the future.

Nanoscale Magneto-mechanical-genetics of Deep Brain Neurons Reversing Motor Deficits in Parkinsonian Mice

Here, we introduce the magneto-mechanical-genetic (MMG)-driven wireless deep brain stimulation (DBS) using magnetic nanostructures for therapeutic benefits in the mouse model of Parkinson's disease (PD). Electrical DBS of the subthalamic nucleus (STN) is an effective therapy for mitigating Parkinson's motor symptoms. However, its broader application is hampered by the requirement for implanted electrodes and the lack of anatomical and cellular specificity. Using the nanoscale magnetic force actuators (m-Torquer), which deliver torque force under rotating magnetic fields to activate pre-encoded Piezo1 ion channels on target neurons, our system enables wireless and STN-specific DBS without implants, addressing key unmet challenges in the DBS field. In both late- and early-stage PD mice, MMG-DBS significantly improved locomotor activity and motor balance by 2-fold compared to untreated PD mice. Moreover, MMG-DBS enabled sustained therapeutic effects. This approach provides a non-invasive and implant-free DBS with cellular targeting capability for the effective treatment of Parkinsonian symptoms.