Transcranial Magneto-Acoustic Stimulation Improves Neuroplasticity in Hippocampus of Parkinson's Disease Model Mice

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.

Research progress on the effects and mechanisms of magnetic field on neurodegenerative diseases

With the progress of modern science and technology, magnetic therapy technology develops rapidly, and many types of magnetic therapy methods continue to emerge, making magnetic therapy one of the main techniques of physiotherapy. With the continuous development of magnetic field research and clinical applications, magnetic therapy, as a non-invasive brain stimulation therapy technology, has attracted much attention due to its potential in the treatment of motor dysfunction, cognitive impairment and speech disorders in patients with neurodegenerative diseases. However, the role of magnetic fields in the prognosis and treatment of neurodegenerative diseases and their mechanisms remain largely unexplored. In this paper, the therapeutic effect and neuroprotective mechanism of the magnetic field on neurodegenerative diseases are reviewed, and the new magnetic therapy techniques are also summarized. Although the neuroprotective mechanism of magnetic field cannot be fully elaborated, it is helpful to promote the application of magnetic field in neurodegenerative diseases and provide a new theoretical basis for the related magnetic field research in the later period.

Effects of transcranial magneto-acoustic stimulation on cognitive function and neural signal transmission in the hippocampal CA1 region of mice

As a new means of brain neuroregulation and research, transcranial magneto-acoustic stimulation (TMAS) uses the coupling effect of ultrasound and a static magnetic field to regulate neural activity in the corresponding brain areas. Calcium ions can promote the secretion of neurotransmitters and play a key role in the transmission of neural signals in brain cognition. In this study, to explore the effects of TMAS on cognitive function and neural signaling in the CA1 region of the hippocampus, TMAS was applied to male 2-month-old C57 mice with a magnetic field strength of 0.3 T and ultrasound intensity of 2.6 W/cm2. First, the efficiency of neural signaling in the CA1 region of the mouse hippocampus was detected by fiber photometry. Second, the effects of TMAS on cognitive function in mice were investigated through multiple behavioral experiments, including spatial learning and memory ability, anxiety and desire for novelty. The experimental results showed that TMAS could improve cognitive function in mice, and the efficiency of neural signaling in the CA1 area of the hippocampus was significantly increased during stimulation and maintained for one week after stimulation. In addition, the neural signaling efficiency in the CA1 area of the hippocampus increased in the open field (OF) experiment and recovered after one week, the neural signaling efficiency in the new object exploration (NOE) experiment was significantly enhanced, and the intensity slowed after one week. In conclusion, TMAS enhances cognitive performance and promotes neural signaling in the CA1 region of the mouse hippocampus.

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.

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.

Transcranial Magneto-Acoustic Stimulation Protects Synaptic Rehabilitation from Amyloid-Beta Plaques via Regulation of Microglial Functions

Transcranial magneto-acoustic stimulation (TMAS), which is characterized by high spatiotemporal resolution and high penetrability, is a non-invasive neuromodulation technology based on the magnetic-acoustic coupling effect. To reveal the effects of TMAS treatment on amyloid-beta (Aβ) plaque and synaptic plasticity in Alzheimer's disease, we conducted a comparative analysis of TMAS and transcranial ultrasound stimulation (TUS) based on acoustic effects in 5xFAD mice and BV2 microglia cells. We found that the TMAS-TUS treatment effectively reduced amyloid plaque loads and plaque-associated neurotoxicity. Additionally, TMAS-TUS treatment ameliorated impairments in long-term memory formation and long-term potentiation. Moreover, TMAS-TUS treatment stimulated microglial proliferation and migration while enhancing the phagocytosis and clearance of Aβ. In 5xFAD mice with induced microglial exhaustion, TMAS-TUS treatment-mediated Aβ plaque reduction, synaptic rehabilitation improvement, and the increase in phospho-AKT levels were diminished. Overall, our study highlights that stimulation of hippocampal microglia by TMAS treatment can induce anti-cognitive impairment effects via PI3K-AKT signaling, providing hope for the development of new strategies for an adjuvant therapy for Alzheimer's disease.

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.

Noninvasive Neuromodulation in Parkinson's Disease: Insights from Animal Models

The mainstay treatments for Parkinson's Disease (PD) have been limited to pharmacotherapy and deep brain stimulation. While these interventions are helpful, a new wave of research is investigating noninvasive neuromodulation methods as potential treatments. Some promising avenues have included transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), electroconvulsive therapy (ECT), and focused ultrasound (FUS). While these methods are being tested in PD patients, investigations in animal models of PD have sought to elucidate their therapeutic mechanisms. In this rapid review, we assess the available animal literature on these noninvasive techniques and discuss the possible mechanisms mediating their therapeutic effects based on these findings.

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

The neuropathological features of Alzheimer's disease include amyloid plaques. Rapidly emerging evidence suggests that Piezo1, a mechanosensitive cation channel, plays a critical role in transforming ultrasound-related mechanical stimuli through its trimeric propeller-like structure, but the importance of Piezo1-mediated mechanotransduction in brain functions is less appreciated. However, apart from mechanical stimulation, Piezo1 channels are strongly modulated by voltage. We assume that Piezo1 may play a role in converting mechanical and electrical signals, which could induce the phagocytosis and degradation of Aβ, and the combined effect of mechanical and electrical stimulation is superior to single mechanical stimulation. Hence, we design a transcranial magneto-acoustic stimulation (TMAS) system, based on transcranial ultrasound stimulation (TUS) within a magnetic field that combines a magneto-acoustic coupling effect electric field and the mechanical force of ultrasound, and applied it to test the above hypothesis in 5xFAD mice. Behavioral tests, in vivo electrophysiological recordings, Golgi-Cox staining, enzyme-linked immunosorbent assay, immunofluorescence, immunohistochemistry, real-time quantitative PCR, Western blotting, RNA sequencing, and cerebral blood flow monitoring were used to assess whether TMAS can alleviate the symptoms of AD mouse model by activating Piezo1. TMAS treatment enhanced autophagy to promote the phagocytosis and degradation of β-amyloid through the activation of microglial Piezo1 and alleviated neuroinflammation, synaptic plasticity impairment, and neural oscillation abnormalities in 5xFAD mice, showing a stronger effect than ultrasound. However, inhibition of Piezo1 with an antagonist, GsMTx-4, prevented these beneficial effects of TMAS. This research indicates that Piezo1 can transform TMAS-related mechanical and electrical stimuli into biochemical signals and identifies that the favorable effects of TMAS on synaptic plasticity in 5xFAD mice are mediated by Piezo1.

A modified mouse model of perioperative neurocognitive disorders exacerbated by sleep fragmentation

Aging is one of the greatest risk factors for postoperative cognitive dysfunction (POCD), also known as perioperative neurocognitive disorder (PND). Animal models of PND are usually induced in mice over 18 months of age, which imposes expensive economic and time costs for PND-related studies. Sleep disorders, including sleep fragmentation, are reported to aggravate memory impairment in neurocognitive-related diseases such as Alzheimer's disease (AD). Therefore, the aim of the present study was to explore whether a PND model could be constructed in younger mice with the help of fragmented sleep. We found that fragmented sleep followed by laparotomy under isoflurane anesthesia could stably induce PND in 15-month-old mice. To determine whether the neurocognitive decline in this model could be salvaged by clinical treatments, we administered repetitive transcranial magnetic stimulation (rTMS) to the model mice before anesthesia and surgery. We found that 10 days of high-frequency rTMS (HF-rTMS) could improve spatial learning and memory deficits in this modified PND model. We are the first to successfully construct a PND model in younger mice,which is more economical, that can be used as an alternative model for future PND studies.

Changes in the Neuronal Architecture of the Hippocampus in a 6-Hydroxydopamine-Lesioned Rat Model of Parkinson Disease

PURPOSE

Parkinson disease (PD) is a progressive neurodegenerative disorder in which dopaminergic (DAergic) systems are destroyed (particularly in the nigrostriatal system), causing both motor and nonmotor symptoms. Hippocampal neuroplasticity is altered in PD animal models, resulting in nonmotor dysfunctions. However, little is known about the precise mechanism underlying the hippocampal dysfunctions in PD.

METHODS

Striatal 6-hydroxydopamine (6-OHDA) infusions were performed unilaterally in adult Sprague Dawley rats. Both motor and nonmotor symptoms alongside the expression of tyrosine hydroxylase (TH) in the substantia nigra and striatum were confirmed in 6-OHDA-lesioned rats. The neuronal architecture in the hippocampus was analyzed by Golgi staining.

RESULTS

During the 7-8 weeks after infusion, the 6-OHDA-lesioned rats exhibited motor and nonmotor dysfunctions (especially anxiety/depression-like behaviors). Rats with unilateral 6-OHDA infusion displayed reduced TH+ immunoreactivity in the ipsilateral nigrostriatal pathway of the brain. Golgi staining revealed that striatal 6-OHDA infusion significantly decreased the dendritic complexity (i.e., number of crossing dendrites, total dendritic length, and branch points) in the ipsilateral hippocampal conus ammonis 1 (CA1) apical/basal and dentate gyrus (DG) subregions. Additionally, the dendritic spine density and morphology were significantly altered in the CA1 apical/basal and DG subregions following striatal 6-OHDA infusion. However, alteration of microglial and astrocytic distributions did not occur in the hippocampus following striatal 6-OHDA infusion.

CONCLUSION

The present study provides anatomical evidence that the structural plasticity in the hippocampus is altered in the late phase following striatal 6-OHDA infusion in rats, possibly as a result of the prolonged suppression of the DAergic system, and independent of neuroinflammation.

Theoretical analysis of effects of transcranial magneto-acoustical stimulation on neuronal spike-frequency adaptation

BACKGROUND

Transcranial magneto-acoustical stimulation (TMAS) is a noninvasive technique that has advantages in spatial resolution and penetration depth. It changes the firing properties of neurons through the current generated by focused ultrasound and a static magnetic field. Spike-frequency adaptation is an important dynamic characteristic of neural information processing.

METHODS

To address the effects of TMAS on neural spike-frequency adaptation, this study employs some ultrasound and magnetic field parameters, such as magnetic flux density, ultrasonic intensity, fundamental ultrasonic frequency, modulation frequency, and duty cycle. Using these different ultrasound and magnetic field parameters, membrane potential curves, spike-frequency curves, and adapted onset spike-frequency curves are exhibited and analyzed.

RESULTS

The results show that spike-frequency adaptation is strongly dependent on ultrasonic intensity and magnetic flux density and is rarely affected by other parameters. However, modulation frequency and duty cycle influence membrane potentials and spike frequencies to some degree.

CONCLUSIONS

This study reveals the mechanism of the effects of TMAS on neural spike-frequency adaptation and serves as theoretical guidance for TMAS experiments.

[Phase amplitude coupling analysis of local field potentials in working memory of rats affected by transcranial magneto-acoustic-electrical stimulation]

Transcranial magneto-acoustic-electrical stimulation is a new non-invasive neuromodulation technology, in which the induced electric field generated by the coupling effect of ultrasound and static magnetic field are used to regulate the neural rhythm oscillation activity in the corresponding brain region. The purpose of this paper is to investigate the effects of transcranial magneto-acoustic-electrical stimulation on the information transfer and communication in neuronal clusters during memory. In the experiment, twenty healthy adult Wistar rats were randomly divided into a control group (five rats) and stimulation groups (fifteen rats). Transcranial magneto-acoustic-electrical stimulation of 0.05~0.15 T and 2.66~13.33 W/cm 2 was applied to the rats in stimulation groups, and no stimulation was applied to the rats in the control group. The local field potentials signals in the prefrontal cortex of rats during the T-maze working memory tasks were acquired. Then the coupling differences between delta rhythm phase, theta rhythm phase and gamma rhythm amplitude of rats in different parameter stimulation groups and control group were compared. The experimental results showed that the coupling intensity of delta and gamma rhythm in stimulation groups was significantly lower than that in the control group ( P<0.05), while the coupling intensity of theta and gamma rhythm was significantly higher than that in the control group ( P<0.05). With the increase of stimulation parameters, the degree of coupling between delta and gamma rhythm showed a decreasing trend, while the degree of coupling between theta and gamma rhythm tended to increase. The preliminary results of this paper indicated that transcranial magneto-acoustic-electrical stimulation inhibited delta rhythmic neuronal activity and enhanced the oscillation of theta and gamma rhythm in the prefrontal cortex, thus promoted the exchange and transmission of information between neuronal clusters in different spatial scales. This lays the foundation for further exploring the mechanism of transcranial magneto-acoustic-electrical stimulation in regulating brain memory function.

Structural Plasticity of the Hippocampus in Neurodegenerative Diseases

Neuroplasticity is the capacity of neural networks in the brain to alter through development and rearrangement. It can be classified as structural and functional plasticity. The hippocampus is more susceptible to neuroplasticity as compared to other brain regions. Structural modifications in the hippocampus underpin several neurodegenerative diseases that exhibit cognitive and emotional dysregulation. This article reviews the findings of several preclinical and clinical studies about the role of structural plasticity in the hippocampus in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. In this study, literature was surveyed using Google Scholar, PubMed, Web of Science, and Scopus, to review the mechanisms that underlie the alterations in the structural plasticity of the hippocampus in neurodegenerative diseases. This review summarizes the role of structural plasticity in the hippocampus for the etiopathogenesis of neurodegenerative diseases and identifies the current focus and gaps in knowledge about hippocampal dysfunctions. Ultimately, this information will be useful to propel future mechanistic and therapeutic research in neurodegenerative diseases.

[Effects of transcranial magneto-acoustic electrical stimulation on calcium signals in prefrontal nerve clusters]

Transcranial magneto-acoustic electrical stimulation (TMAES) is a novel method of brain nerve regulation and research, which uses induction current generated by the coupling of ultrasound and magnetic field to regulate neural electrical activity in different brain regions. As the second special envoy of nerve signal, calcium plays a key role in nerve signal transmission. In order to investigate the effect of TMAES on prefrontal cortex electrical activity, 15 mice were divided into control group, ultrasound stimulation (TUS) group and TMAES group. The TMAES group received 2.6 W/cm 2 and 0.3 T of magnetic induction intensity, the TUS group received only ultrasound stimulation, and the control group received no ultrasound and magnetic field for one week. The calcium ion concentration in the prefrontal cortex of mice was recorded in real time by optical fiber photometric detection technology. The new object recognition experiment was conducted to compare the behavioral differences and the time-frequency distribution of calcium signal in each group. The results showed that the mean value of calcium transient signal in the TMAES group was (4.84 ± 0.11)% within 10 s after the stimulation, which was higher than that in the TUS group (4.40 ± 0.10)% and the control group (4.22 ± 0.08)%, and the waveform of calcium transient signal was slower, suggesting that calcium metabolism was faster. The main energy band of the TMAES group was 0-20 Hz, that of the TUS group was 0-12 Hz and that of the control group was 0-8 Hz. The cognitive index was 0.71 in the TMAES group, 0.63 in the TUS group, and 0.58 in the control group, indicating that both ultrasonic and magneto-acoustic stimulation could improve the cognitive ability of mice, but the effect of the TMAES group was better than that of the TUS group. These results suggest that TMAES can change the calcium homeostasis of prefrontal cortex nerve clusters, regulate the discharge activity of prefrontal nerve clusters, and promote cognitive function. The results of this study provide data support and reference for further exploration of the deep neural mechanism of TMAES.

The Influence of Transcranial Magnetoacoustic Stimulation Parameters on the Basal Ganglia-Thalamus Neural Network in Parkinson's Disease

Objective: Parkinson's disease (PD) is a degenerative disease of the nervous system that frequently occurs in the aged. Transcranial magnetoacoustic stimulation (TMAS) is a neuronal adjustment method that combines sound fields and magnetic fields. It has the characteristics of high spatial resolution and noninvasive deep brain focusing. Methods: This paper constructed a simulation model of TMAS based on volunteer's skull computer tomography, phased controlled transducer and permanent magnet. It simulates a transcranial focused sound pressure field with the Westervelt equation and builds a basal ganglia and thalamus neural network model in the PD state based on the Hodgkin-Huxley model. Results: A biased sinusoidal pulsed ultrasonic TMAS induced current with 0.3 T static magnetic field induction and 0.2 W⋅cm-2 sound intensity can effectively modulate PD states with RI ≥ 0.633. The magnitude of magnetic induction strength was changed to 0.2 and 0.4 T. The induced current was the same when the sound intensity was 0.4 and 0.1 W⋅cm-2. And the sound pressure level is in the range of -1 dB (the induced current difference is less than or equal to 0.019 μA⋅cm-2). TMAS with a duty cycle of approximately 50% can effectively modulates the error firings in the PD neural network with a relay reliability not less than 0.633. Conclusion: TMAS can modulates the state of PD.

Resistance exercise improves short-term memory through inactivation of NF-κB pathway in mice with Parkinson disease

Dysfunctions of Parkinson disease (PD) are classified into motor dysfunction, autonomic nervous system dysfunction, and nonmotor dysfunction, and clinical symptoms such as muscle stiffness, tremors, speech disorders, balance disorders, and slow movements appear. Resistance exercise is a main compartment of exercise programs for PD patient. The effect of resistant exercise on short-term memory in PD mice was studied in relation to the activation of nuclear factor (NF)-κB pathway. PD was induced by subcutaneous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. For resistance exercise, mice performed ladder climbing 5 days per week for 5 weeks. Step-down avoidance test for short-term memory, enzyme-linked immunoassay for tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, Western bot for NF-κB, NF-κB inhibitor (IκB)-α, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), and Bcl-2, and immunohistochemistry for cleaved caspase-3 were done. Latency time was shortened, TNF-α, IL-6, and IL-1β concentration was increased, NF-κB expression and IκB-α phosphorylation were increased, cleaved caspase-3 and Bax expression was enhanced, and Bcl-2 expression was suppressed by PD induction. Latency time was lengthened, TNF-α, IL-6, and IL-1β concentration was decreased, NF-κB expression and IκB-α phosphorylation were suppressed, cleaved caspase-3 and Bax expression was decreased, and Bcl-2 expression was increased in PD mice by resistance exercise or levodopa treatment. Resistance exercise improved short-term memory by inhibiting secretion of proinflammatory cytokines and apoptosis through inactivation of NF-κB. These effects of resistance exercise were similar to levodopa treatment.