Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model

Low-intensity pulsed ultrasound relieved the diabetic peripheral neuropathy in mice via anti-oxidative stress mechanism

Diabetic peripheral neuropathy (DPN), as one of the most prevalent complications of diabetes, leads to significant pain and financial burden to patients. Currently, there was no effective treatment for DPN since the glucose control was just a prevention and the drug therapy only relieved the DPN pain. As a non-invasive physical therapy, low-intensity pulsed ultrasound (LIPUS) is utilized in the musculoskeletal and nerve injuries therapy. Studies revealed that LIPUS could regenerate nerves by the mechanical stimulation via oxidative stress pathway, which was thought as the important factor for DPN, and might have potential in the DPN therapy. This study aimed to identify a new therapeutic strategy for DPN using LIPUS. We analyzed the therapy effect and explored the therapeutic mechanism of LIPUS on DPN in mice. This study involved animal experiments and C57BL/6J mice were randomly assigned to DPN model and Sham groups. The DPN model group was fed a high-fat chow diet and injected with streptozotocin (STZ) for 3 consecutive days (40 mg/kg/d), whereas the Sham group was fed a normal diet and injected with an equal volume of sodium citrate buffer. After the DPN model confirmed with the 84-day modeling process, the DPN mice were randomly allocated into the DPN group and the LIPUS group. The LIPUS group underwent ultrasound treatments with a center frequency of 1 MHz, a duty cycle of 20 %, and a spatial average temporal average intensity (ISATA) of 200 mW/cm2 for 20 min/d, 5 d/w. After the 56-day treatment, all mice were euthanized. LIPUS therapeutic effects were evaluated through measurements of fasting blood glucose (FBG), behavioral tests, oxidative stress tests, morphological analysis, immunofluorescence, and western blot analysis. The results indicated that DPN mice had significantly higher FBG levels (28.77 ± 2.95 mmol/L) compared with sham mice (10.31 ± 1.49 mmol/L). Additionally, DPN mice had significantly lower mechanical threshold (4.13 ± 0.92 g) and higher thermal latency (16.20 ± 2.39 s) compared with the sham mice (7.31 ± 0.83 g, 11.67 ± 1.21 s). After receiving LIPUS treatment, the glucose tolerance tests (GTT) suggested that LIPUS treatment improved glucose tolerance, which was shown by a decrease in the area under the curve (AUC) for glucose in the LIPUS group (AUC = 2452 ± 459.33 min*mmol/L) compared with the DPN group (AUC = 3271 ± 420.90 min*mmol/L). Behavioral tests showed that LIPUS treatment significantly alleviated DPN-induced abnormalities by improving the mechanical threshold from 2.79 ± 0.79 g in the DPN group to 5.50 ± 1.00 g in the LIPUS group, and significantly decreasing thermal latency from 12.38 ± 1.88 s in the DPN group to 9.49 ± 2.31 s in the LIPUS group. Morphological observations revealed that DPN mice had a thinning and irregularly shaped myelin sheath, with 61.04 ± 5.60 % of abnormal nerve fibers in the sciatic nerve in LIPUS group, compared with 49.76 ± 4.88 % of abnormal nerve fibers in the LIPUS-treated group. Additionally, LIPUS treatment increased the mean fluorescence intensity of the associated nerve regeneration protein (i.e., Nf200) from 27.81 ± 0.32 arbitrary units in the DPN group to 37.62 ± 0.36 arbitrary units in the LIPUS group. Western blot and immunofluorescence analysis showed that LIPUS treatment significantly reduced Keap1 expression to 0.04 ± 0.06 relative units, compared with 0.17 ± 0.30 in the DPN group. Furthermore, immunofluorescence analysis revealed that LIPUS treatment promoted the production of its downstream antioxidant protein, heme oxygenase-1 (HO-1), with an increase in the fluorescence intensity from 27.81 ± 0.32 arbitrary units in the DPN group to 37.62 ± 0.36 arbitrary units in the LIPUS-treated group. The fluorescence intensity of Nrf2 was significantly higher in the LIPUS group, increasing from 4.90 ± 0.25 arbitrary units in the DPN group to 15.18 ± 2.13 arbitrary units in the LIPUS-treated group. Additionally, the malondialdehyde (MDA) levels, an indicator of oxidative stress, were significantly reduced in the serum, from 5.40 ± 0.48 nmol/ml in the DPN group to 4.64 ± 0.16 nmol/ml in the LIPUS-treated group, and in the sciatic nerve, from 16.17 ± 5.88 nmol/mg protein to 4.67 ± 2.10 nmol/mg protein, suggesting the oxidative stress was inhibited by LIPUS. This study demonstrated for the first time that LIPUS could relive DPN through anti-oxidative stress process. This study suggests that LIPUS might be a new therapy strategy for DPN.

Integrating network pharmacology and in vivo study to explore the anti-Alzheimer's potential of Bergenia ligulata and Nelumbo nucifera

Amyloid plaque buildup, tau protein tangles, oxidative stress, and neuronal death are the hallmarks of Alzheimer's disease (AD). Using network pharmacology, molecular docking, and in vivo experiments, this study investigated the neuroprotective potential of Bergenia ligulata (BL) and Nelumbo nucifera (NN) against aluminum chloride (AlCl₃)-induced AD. Network pharmacology focused on important biomarker proteins like acetylcholinesterase (AChE), BCL2, and caspase-3 to identify 74 bioactive targets linked to AD. The evaluation of ligand-protein interactions was done using molecular docking. Male Wistar rats were exposed to AlCl₃ to cause AD-like pathology in vivo, and a combination treatment of BL and NN at varying doses was provided. Apoptosis markers (BCL2, caspase-3), biochemical investigations (AChE activity, oxidative stress markers-GSH, SOD, catalase, and lipid peroxidation), behavioral evaluations (elevated plus maze, conditioned avoidance test), and histopathological analyses were investigated. The combination of BL and NN demonstrated substantial neuroprotection in a dose-dependent manner. Reduced AChE levels point out improved cholinergic activity. Oxidative stress indicators showed improvement, with lower levels of malondialdehyde and higher anti-oxidant levels of GSH, SOD, and catalase. Apoptotic markers showed an increase in BCL2 expression and a decrease in caspase-3, suggesting anti-apoptotic effects. Reduced neuronal degeneration in the cortex and hippocampal regions was confirmed by histopathology of the brain. The synergistic potential of BL and NN demonstrated potent neuroprotective effects by modulating AChE activity, reducing oxidative stress, increasing anti-oxidant levels, and inhibiting apoptosis. These findings highlighted the potential of BL and NN as a new therapeutic approach for the AD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-025-04274-w.

Extension and validation of a physiologically based toxicokinetic model for risk assessment of aluminium exposure in humans

The safety of aluminium (Al) exposure from sources such as food, parenteral nutrition or adjuvanted medicinal products is still a matter of uncertainty. Since toxicokinetic studies in humans are lacking, model predictions are warranted for risk assessment. Recently, we established a physiologically based toxicokinetic (PBTK) model for Al built on a comprehensive toxicokinetic26 Al database, which could describe Al biokinetics in rats and human adults after single oral and intravenous doses of soluble Al salts. Since then, we have substantially amended the model, rendering it applicable to accurately represent children and their dynamically changing physiology (including maturating renal function in neonates and increased bone turnover during puberty). Also, additional sources of exposure were implemented, including vaccinations, subcutaneous allergen immunotherapies, food, antacids and parenteral nutrition. The model predictions in plasma and tissues were then compared to own published data and literature Al measurements after exposure from food (human reference values), parenteral nutrition (toxic levels in children and adults), adjuvanted allergen products or vaccines in rats and humans, and whole-body retention data. Al levels were predicted remarkably well, in plasma and toxicologically important tissues like bone, liver and brain. To our knowledge, this is the first Al PBTK model in humans ready for use in regulatory risk assessment, allowing to simulate Al exposure in children and adults from various sources of Al exposure like food and drinking water, Al contaminations in parenteral nutrition solutions, or poorly soluble Al complexes in medicinal products including Al-adjuvanted immunotherapeutics and vaccines.

Ultrasound-Induced Synchronized Neural Activities at 40 Hz and 200 Hz Entrained Corresponded Oscillations and Improve Alzheimer's Disease Memory

AIMS

Neurological diseases like Alzheimer's disease (AD) with cognitive deficits show impaired theta, gamma, and ripple bands. Restoring these oscillations may be crucial for rescuing cognitive functions. Low-intensity transcranial ultrasound stimulation (TUS), a noninvasive neuromodulation method, offers high spatial resolution and deep penetration. However, it remains unclear how 40 Hz and 200 Hz TUS may improve memory in AD by regulating hippocampal oscillations.

METHODS

We applied 40 Hz and 200 Hz TUS to the CA1 region of AD mice, performing memory assessments and CA1 electrophysiology recordings simultaneously.

RESULTS

Our results showed that both 40 Hz and 200 Hz TUS significantly improved memory performance in AD mice by targeting the dorsal hippocampus and increasing power in corresponding frequency bands. Specifically, 40 Hz TUS enhanced gamma and ripple bands, while 200 Hz TUS strongly affected both. This enhancement increased during stimulation and persisted 5 days poststimulation. Improved coupling between theta and gamma oscillations indicated better hippocampal coordination with other brain regions. Additionally, 40 Hz TUS raised sharp wave ripple (SPW-Rs) incidence, and 200 Hz TUS increased both SPW-R incidence and duration, contributing to memory improvement. Behavioral performance significantly improved with TUS at both frequencies.

CONCLUSION

Ultrasound-induced synchronized neural activities at 40 Hz and 200 Hz entrained corresponding oscillations and improved memory in Alzheimer's disease.

Effects of blood-brain barrier opening using ultrasound on tauopathies: A systematic review

Blood-brain barrier opening with ultrasound can potentiate drug efficacy in the treatment of brain pathologies and also provides therapeutic effects on its own. It is an innovative tool to transiently, repeatedly and safely open the barrier, with studies showing beneficial effects in both preclinical models for Alzheimer's disease and recent clinical studies. The first preclinical and clinical work has mainly shown a decrease in amyloid burden in mice models and in patients. However, Alzheimer's disease pathology also encompasses tauopathy, which is closely related to cognitive decline, making it a crucial therapeutic target. The effects of blood-brain barrier opening with ultrasound have been rarely assessed on tau and are still unclear.

METHODS

This systematic review, conducted through searches using Pubmed, Embase, Web of Science and Cochrane Central databases, extracted results of 15 studies reporting effects of blood-brain barrier opening using ultrasound on tau proteins.

RESULTS

This review of the literature indicates that blood-brain barrier opening using ultrasound can decrease the extent of the tau pathology or potentialize the effect of a therapeutic drug. However, selected studies report paradoxically that blood-brain barrier opening can increase tau pathology burden and induce brain damage.

DISCUSSION

Apparent discrepancies between reports could originate from the variability in protocols or analytical methods that may impact the effects of blood-brain barrier opening with ultrasound on tauopathies, glial populations, tissue integrity and functional outcomes.

CONCLUSION

This calls for a better standardization effort combined with improved methodologies allowing between-studies comparisons, and for further understanding of the effects of blood-brain barrier opening on tau pathology as an essential prerequisite before translation to clinic.

Effect of a single session of transcranial pulse stimulation (TPS) on resting tremor in patients with Parkinson's disease

INTRODUCTION

Tremor is a common symptom in movement disorders and is evident at rest in Parkinson's Disease (PD). In PD, tremor may be responsive to brain stimulation, ranging from Deep Brain Stimulation to Transcranial Magnetic Stimulation. Transcranial Pulse Stimulation (TPS) is a novel/painless/non-invasive technique which appears to induce biomolecular changes through shock waves. Here, as one of the first studies in the field of PD, we exploratively investigate the possibility to observe changes in tremor, induced by single-session TPS delivered on the motor cortex of PD patients.

METHODS

TPS was delivered in 16 patients. Of these, 9 were admitted to sham (placebo). Resting tremor was measured at baseline (T0), after TPS (T1), and after 24 ​h from intervention (T2).

RESULTS

At baseline, tremor was always present. After TPS, tremor reduction was noted at T1 and T2 (compared to T0 and placebo). We noted a decrease in the amplitude of resting tremor (not its frequency).

DISCUSSION

TPS is a non-invasive technique that may be a novel solution for reducing tremor in PD, lasting at least 24 ​h after single-sessions. No side effects were reported. We discuss evidence suggesting potential physiological changes in mechanisms of neural circuits that are affected in PD.

Volume Changes in Brain Subfields of Patients with Alzheimer's Disease After Transcranial Ultrasound Stimulation

Background/Objectives: Alzheimer's disease (AD) is characterized by progressive brain atrophy marked by cognitive decline and memory loss, which significantly affect patients' quality of life. Transcranial ultrasound stimulation (TUS) is a potential physical treatment for AD patients. However, the specific brain regions stimulated by TUS and its therapeutic effects remain unclear. Methods: In this study, magnetic resonance imaging (MRI) and FreeSurfer segmentation were employed to assess alterations in the brain volume of AD patients after TUS. Results: Our findings revealed significant volume increases in the corpus callosum (CC) and lateral orbitofrontal cortex (lOFC) in the TUS group. Moreover, the volumetric changes in the CC were strongly correlated with improvements in the Mini-Mental State Examination score, which is a widely used measure of cognitive function of AD patients. Conclusions: TUS has the potential to alleviate disease progression and offers a non-invasive therapeutic approach to the improvement of cognitive function in AD patients.

Label free, capillary-scale blood flow mapping in vivo reveals that low-intensity focused ultrasound evokes persistent dilation in cortical microvasculature

Non-invasive, low intensity focused ultrasound is an emerging neuromodulation technique that offers the potential for precision, personalized therapy. An increasing body of research has identified mechanosensitive ion channels that can be modulated by FUS and support acute electrical activity in neurons. However, neuromodulatory effects that persist from hours to days have also been reported. The brain's ability to provide blood flow to electrically active regions involves a multitude of non-neuronal cell types and signaling pathways in the cerebral vasculature; an open question is whether persistent effects can be attributed, at least partly, to vascular mechanisms. Using an in vivo optical approach, we found that microvasculature, and not larger vessels, exhibit significant persistent dilation following sonication without the use of microbubbles. This finding reveals a heretofore unseen aspect of the effects of FUS in vivo and indicates that concurrent changes in neurovascular function may partially underly persistent neuromodulatory effects.

Eugenol attenuates aluminium-induced neurotoxicity in rats by inhibiting the activation of STAT3 and NF-кB

Aluminium is a common metallic toxicant that easily penetrates the brain and exerts severe pathological effects e.g., oxidative stress, inflammation and neurodegeneration. Eugenol is a natural phenolic compound possessing numerous therapeutic properties including antioxidant, anti-inflammatory and neuroprotective. The compound has also been reported to interfere with important transcription factors like STAT3 and NF-кB. Thus, the present study intended to explore the therapeutic potential of eugenol in aluminium neurotoxicity. Rats were administered AlCl3 (100 mg/kg b. wt., orally) and eugenol (200 mg/kg b. wt., orally) alone or in combination for 45 days. The results revealed that AlCl3 administration increases acetylcholinesterase (AChE) activity, lipid peroxidation (LPO), and protein oxidation (PO) along with decreasing superoxide dismutase (SOD) and catalase (CAT) activities, and glutathione (GSH) content in the cortex and hippocampus regions of the brain. Moreover, AlCl3 induces neuronal loss and astroglial activation in both brain areas. The study further revealed that AlCl3 also increases the expression of transcription factors STAT3 and NF-кB in neurons and astrocytes of the cortex and hippocampus. However, co-administration of eugenol with AlCl3 restored the enzymatic activities of AChE, SOD and CAT, and GSH content, and rescued the cortex and hippocampus from LPO, PO, neuronal loss and astroglial activation. Furthermore, the study reported that eugenol reverses the expression pattern of STAT3 and NF-кB in AlCl3-intoxicated rats. In conclusion, the study suggests that eugenol ameliorates oxidative stress, neuronal loss and reactive astrogliosis in aluminium-induced neurotoxicity by inhibiting signalling molecules, STAT3 and NF-кB.

Non-Drug and Non-Invasive Therapeutic Options in Alzheimer's Disease

Despite the massive efforts of modern medicine to stop the evolution of Alzheimer's disease (AD), it affects an increasing number of people, changing individual lives and imposing itself as a burden on families and the health systems. Considering that the vast majority of conventional drug therapies did not lead to the expected results, this review will discuss the newly developing therapies as an alternative in the effort to stop or slow AD. Focused Ultrasound (FUS) and its derived Transcranial Pulse Stimulation (TPS) are non-invasive therapeutic approaches. Singly or as an applied technique to change the permeability of the blood-brain-barrier (BBB), FUS and TPS have demonstrated the benefits of use in treating AD in animal and human studies. Adipose-derived stem Cells (ADSCs), gene therapy, and many other alternative methods (diet, sleep pattern, physical exercise, nanoparticle delivery) are also new potential treatments since multimodal approaches represent the modern trend in this disorder research therapies.

A new bithiophene inhibited amyloid-β accumulation and enhanced cognitive function in the hippocampus of aluminum-induced Alzheimer's disease in adult rats

BACKGROUND

Alzheimer's disease (AD) is a progressive and irreversible neurological disorder that gradually deteriorates an individual's ability to carry out even the simplest tasks.

OBJECTIVE

This study was undertaken to investigate the potential therapeutic efficacy of a novel bithiophene in a rat model of aluminum-induced AD pathology.

METHODS

A total of 108 adult male albino rats weighing 160 ± 20 g, were randomly assigned to six groups: (1) a control group administered DMSO, (2) group receiving a high dose of bithiophene (1 mg/kg), (3) a model group received AlCl3 (100 mg/kg), those rats were then treated by either (4) bithiophene low dose (0.5 mg/kg), (5) high dose (1 mg/kg), or (6) memantine (20 mg/kg).

RESULTS

Low dose bithiophene treatment was a promising strategy for mitigating oxidative stress and improving synaptic plasticity. This was demonstrated by reductions in malondialdehyde level, and increased activities of superoxide dismutase and catalase, and elevated glutathione content. Likewise, low dose bithiophene enhanced synaptic plasticity through a reduction in excitatory glutamate and norepinephrine levels, while increasing dopamine. Moreover, bithiophene significantly downregulated the expression of GSAP, GSK3-β, and p53, which are implicated in AD progression. This treatment also decreased caspase 3 and amyloid-β (Aβ1-42) accumulation in the hippocampus. Finally, behavioral assessments revealed that low dose bithiophene significantly enhanced learning abilities, as proved by Morris water maze.

CONCLUSIONS

Low dose bithiophene mitigated AD through ameliorating oxidative stress, promoting synaptic plasticity, inhibiting the Aβ accumulation, and enhancing the cognitive functions in a rat model.

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.

Focused Ultrasound for Neurodegenerative Diseases

Neurodegenerative diseases are a leading cause of death and disability and pose a looming global public health crisis. Despite progress in understanding biological and molecular factors associated with these disorders and their progression, effective disease modifying treatments are presently limited. Focused ultrasound (FUS) is an emerging therapeutic strategy for Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In these contexts, applications of FUS include neuroablation, neuromodulation, and/or blood-brain barrier opening with and without facilitated intracerebral drug delivery. Here, the authors review preclinical evidence and current and emerging applications of FUS for neurodegenerative diseases and summarize future directions in the field.

Optimized ultrasound neuromodulation for non-invasive control of behavior and physiology

Focused ultrasound can non-invasively modulate neural activity, but whether effective stimulation parameters generalize across brain regions and cell types remains unknown. We used focused ultrasound coupled with fiber photometry to identify optimal neuromodulation parameters for four different arousal centers of the brain in an effort to yield overt changes in behavior. Applying coordinate descent, we found that optimal parameters for excitation or inhibition are highly distinct, the effects of which are generally conserved across brain regions and cell types. Optimized stimulations induced clear, target-specific behavioral effects, whereas non-optimized protocols of equivalent energy resulted in substantially less or no change in behavior. These outcomes were independent of auditory confounds and, contrary to expectation, accompanied by a cyclooxygenase-dependent and prolonged reduction in local blood flow and temperature with brain-region-specific scaling. These findings demonstrate that carefully tuned and targeted ultrasound can exhibit powerful effects on complex behavior and physiology.

Low-intensity transcranial ultrasound stimulation modulates neurovascular coupling in mouse models of Alzheimer's disease

Neurovascular coupling plays an important role in the progression of Alzheimer's disease. However, it is unclear how ultrasound stimulation modulates neurovascular coupling in Alzheimer's disease. Here, we found that (i) transcranial ultrasound stimulation modulates the time domain and frequency domain characteristics of cerebral blood oxygen metabolism in Alzheimer's disease mice; (ii) transcranial ultrasound stimulation can significantly modulate the relative power of theta and gamma frequency of local field potential in Alzheimer's disease mice; and (iii) transcranial ultrasound stimulation can significantly modulate the neurovascular coupling in time domain and frequency domain induced by forepaw electrical stimulation in Alzheimer's disease mice. It provides a research basis for the clinical application of transcranial ultrasound stimulation in Alzheimer's disease patients.

Therapeutic ultrasound: an innovative approach for targeting neurological disorders affecting the basal ganglia

The basal ganglia are involved in motor control and action selection, and their impairment manifests in movement disorders such as Parkinson's disease (PD) and dystonia, among others. The complex neuronal circuitry of the basal ganglia is located deep inside the brain and presents significant treatment challenges. Conventional treatment strategies, such as invasive surgeries and medications, may have limited effectiveness and may result in considerable side effects. Non-invasive ultrasound (US) treatment approaches are becoming increasingly recognized for their therapeutic potential for reversibly permeabilizing the blood-brain barrier (BBB), targeting therapeutic delivery deep into the brain, and neuromodulation. Studies conducted on animals and early clinical trials using ultrasound as a therapeutic modality have demonstrated promising outcomes for controlling symptom severity while preserving neural tissue. These results could improve the quality of life for patients living with basal ganglia impairments. This review article explores the therapeutic frontiers of ultrasound technology, describing the brain mechanisms that are triggered and engaged by ultrasound. We demonstrate that this cutting-edge method could transform the way neurological disorders associated with the basal ganglia are managed, opening the door to less invasive and more effective treatments.

Therapeutic effects of a new bithiophene against aluminum -induced Alzheimer's disease in a rat model: Pathological and ultrastructural approach

Alzheimer's disease (AD) remains of unknown etiology and lacks a cure. This study aimed to evaluate the therapeutic potential of a novel bithiophene derivative at two doses against AlCl3-induced AD in a rat model. Adult male rats (Rattus norvegicus) were divided into six groups (n=6): Group one consisted of naïve animals, group two received bithiophene (1 mg/kg) every other day for 30 days, and groups 3-6 were subjected to AlCl3 (100 mg/kg, equivalent to 20.23 mg Al3+) for 45 consecutive days. Groups four and five received low (0.5 mg/kg) or high (1 mg/kg) doses of bithiophene, respectively. Group six received memantine (20 mg/kg) daily for 30 days. All treatments were administered orally. Aluminum exposure resulted in severe degeneration of both histological and ultrastructural aspects of cells. Administration of the low dose of bithiophene significantly restored the number of CA1 pyramidal cells and the thickness of the stratum granulosum of the dentate gyrus. However, the high dose of bithiophene increased viable CA1 pyramidal cell numbers significantly without restoring the thickness of the stratum granulosum or reducing vacuolization or pyknotic changes. The low dose of bithiophene restored the normal histological and cytological structure of both cortical and hippocampal neurons affected by dementia. Further investigation is required to explore the molecular mechanisms underlying the ameliorative effects on Alzheimer's disease-induced deteriorations in the cortex and hippocampus.

Low-intensity pulsed ultrasound modulates disease progression in the SOD1G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the brain and spinal cord, and there are no effective drug treatments. Low-intensity pulsed ultrasound (LIPUS) has garnered attention as a promising noninvasive neuromodulation method. In this study, we investigate its effects on the motor cortex and underlying mechanisms using the SOD1G93A mouse model of ALS. Our results show that LIPUS treatment delays disease onset and prolongs lifespan in ALS mice. LIPUS significantly increases cerebral blood flow in the motor cortex by preserving vascular endothelial cell integrity and increasing microvascular density, which may be mediated via the ion channel TRPV4. RNA sequencing analysis reveals that LIPUS substantially reduces the expression of genes associated with neuroinflammation. These findings suggest that LIPUS applied to the motor cortex may represent a potentially effective therapeutic tool for the treatment of ALS.

Label free, capillary-scale blood flow mapping in vivo reveals that low intensity focused ultrasound evokes persistent dilation in cortical microvasculature

Non-invasive, low intensity focused ultrasound (FUS) is an emerging neuromodulation technique that offers the potential for precision, personalized therapy. An increasing body of research has identified mechanosensitive ion channels that can be modulated by FUS and support acute electrical activity in neurons. However, neuromodulatory effects that persist from hours to days have also been reported. The brain's ability to provide targeted blood flow to electrically active regions involve a multitude of non-neuronal cell types and signaling pathways in the cerebral vasculature; an open question is whether persistent effects can be attributed, at least partly, to vascular mechanisms. Using a novel in vivo optical approach, we found that microvascular responses, unlike larger vessels which prior investigations have explored, exhibit persistent dilation following sonication without the use of microbubbles. This finding and approach offers a heretofore unseen aspect of the effects of FUS in vivo and indicate that concurrent changes in neurovascular function may partially underly persistent neuromodulatory effects.

Recent advancement of sonogenetics: A promising noninvasive cellular manipulation by ultrasound

Recent advancements in biomedical research have underscored the importance of noninvasive cellular manipulation techniques. Sonogenetics, a method that uses genetic engineering to produce ultrasound-sensitive proteins in target cells, is gaining prominence along with optogenetics, electrogenetics, and magnetogenetics. Upon stimulation with ultrasound, these proteins trigger a cascade of cellular activities and functions. Unlike traditional ultrasound modalities, sonogenetics offers enhanced spatial selectivity, improving precision and safety in disease treatment. This technology broadens the scope of non-surgical interventions across a wide range of clinical research and therapeutic applications, including neuromodulation, oncologic treatments, stem cell therapy, and beyond. Although current literature predominantly emphasizes ultrasonic neuromodulation, this review offers a comprehensive exploration of sonogenetics. We discuss ultrasound properties, the specific ultrasound-sensitive proteins employed in sonogenetics, and the technique's potential in managing conditions such as neurological disorders, cancer, and ophthalmic diseases, and in stem cell therapies. Our objective is to stimulate fresh perspectives for further research in this promising field.

Microglia and Astrocytes in Alzheimer's Disease: Significance and Summary of Recent Advances

Alzheimer's disease, one of the most common forms of dementia, is characterized by a slow progression of cognitive impairment and neuronal loss. Currently, approved treatments for AD are hindered by various side effects and limited efficacy. Despite considerable research, practical treatments for AD have not been developed. Increasing evidence shows that glial cells, especially microglia and astrocytes, are essential in the initiation and progression of AD. During AD progression, activated resident microglia increases the ability of resting astrocytes to transform into reactive astrocytes, promoting neurodegeneration. Extensive clinical and molecular studies show the involvement of microglia and astrocyte-mediated neuroinflammation in AD pathology, indicating that microglia and astrocytes may be potential therapeutic targets for AD. This review will summarize the significant and recent advances of microglia and astrocytes in the pathogenesis of AD in three parts. First, we will review the typical pathological changes of AD and discuss microglia and astrocytes in terms of function and phenotypic changes. Second, we will describe microglia and astrocytes' physiological and pathological role in AD. These roles include the inflammatory response, "eat me" and "don't eat me" signals, Aβ seeding, propagation, clearance, synapse loss, synaptic pruning, remyelination, and demyelination. Last, we will review the pharmacological and non-pharmacological therapies targeting microglia and astrocytes in AD. We conclude that microglia and astrocytes are essential in the initiation and development of AD. Therefore, understanding the new role of microglia and astrocytes in AD progression is critical for future AD studies and clinical trials. Moreover, pharmacological, and non-pharmacological therapies targeting microglia and astrocytes, with specific studies investigating microglia and astrocyte-mediated neuronal damage and repair, may be a promising research direction for future studies regarding AD treatment and prevention.

Effects of Transcranial Ultrasound Stimulation on Blood Oxygen Metabolism and Brain Rhythms in Nitroglycerin-Induced Migraine Mice

OBJECTIVES

In this study, we aimed to investigate the regulatory mechanism of transcranial ultrasound stimulation (TUS) on nitroglycerin-induced migraine in mice.

MATERIALS AND METHODS

The experiment was divided into four groups, namely, the normal saline control group (n = 9), ultrasound stimulation control group (n = 6), nitroglycerin-induced migraine group (n = 9), and ultrasound stimulation group (n = 9). The behavior, blood oxygen metabolism, and brain rhythm distribution of the four groups were analyzed.

RESULTS

We found that after TUS, the movement time and speed of mice with migraine are modulated to those of the control groups, and the number of head scratching and grooming events is significantly reduced. TUS increased the deoxygenated hemoglobin, and the power of the 4-to-40 Hz frequency band of local field potentials in the cortex of migraine mice. TUS also decreased the expression of plasma calcitonin gene-related peptide and cortical c-Fos protein.

CONCLUSIONS

Ultrasound stimulation can regulate brain rhythm and blood oxygen metabolism and reduce migraine symptoms in mice. The regulatory mechanism may be related to reducing calcitonin gene-related peptide in blood vessels.

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.

Low-Intensity Pulsed Ultrasound Protects SH-SY5Y Cells Against 6-Hydroxydopamine-Induced Neurotoxicity by Upregulating Neurotrophic Factors

OBJECTIVE

Neonatal hypoxic-ischemic brain damage (HIBD) can have long-term implications on patients' physical and mental health, yet the available treatment options are limited. Recent research has shown that low-intensity pulsed ultrasound (LIPUS) holds promise for treating neurodegenerative diseases and traumatic brain injuries. Our objective was to explore the therapeutic potential of LIPUS for HIBD.

METHODS

Due to the lack of a suitable animal model for neonatal HIBD, we will initially simulate the therapeutic effects of LIPUS on neuronal cells under oxidative stress and neuroinflammation using cell experiments. Previous studies have investigated the biologic responses following intracranial injection of 6-hydroxydopamine (6-OHDA). In this experiment, we will focus on the biologic effects produced by LIPUS treatment on neuronal cells (specifically, SH-SY5Y cells) without the presence of other neuroglial cell assistance after stimulation with 6-OHDA.

RESULTS

We found that (i) pulsed ultrasound exposure, specifically three-intermittent sonication at intensities ranging from 0.1 to 0.5 W/cm², did not lead to a significant decrease in viability among SH-SY5Y cells; (ii) LIPUS treatment exhibited a positive effect on cell viability, accompanied by an increase in glial cell-derived neurotrophic factor (GDNF) levels and a decrease in caspase three levels; (iii) the administration of 6-OHDA had a significant impact on cell viability, resulting in a decrease in both brain cell-derived neurotrophic factor (BDNF) and GDNF levels, while concurrently elevating caspase three and matrix metalloproteinase-9 (MMP-9) levels; and (iv) LIPUS treatment demonstrated its potential to alleviate the changes induced by 6-OHDA, particularly in the levels of BDNF, GDNF, and tyrosine hydroxylase (TH).

CONCLUSION

LIPUS treatment may possess partial therapeutic capabilities for SH-SY5Y cells damaged by 6-OHDA neurotoxicity. Our findings enhance our understanding of the effects of LIPUS treatment on cell viability and its modulation of key factors involved in the pathophysiology of HIBD and show the promising potential of LIPUS as an alternative therapeutic approach for neonates with HIBD.

New bithiophene derivative attenuated Alzheimer's disease induced by aluminum in a rat model via antioxidant activity and restoration of neuronal and synaptic transmission

BACKGROUND

One of the hypotheses that leads to an increased incidence of Alzheimer's disease (AD) is the accumulation of aluminum in the brain's frontal cortex. The present study aimed to evaluate the therapeutic role of a novel bithiophene derivative at two doses against AlCl3-induced AD in a rat model.

METHODOLOGY

Adult male rats were divided into six groups, 18 rats each. Group 1: naïve animals, group 2: animals received a daily oral administration of bithiophene dissolved in DMSO (1 mg/kg) for 30 days every other day, groups 3-6: animals received a daily oral administration of AlCl3 (100 mg/kg/day) for 45 consecutive days. Groups 4 and 5 received an oral administration of low or high dose of the bithiophene (0.5 or 1 mg/kg, respectively). Group 6; Animals were treated with a daily oral dose of memantine (20 mg/kg) for 30 consecutive days.

MAIN FINDINGS

Al disturbed the antioxidant milieu, elevated the lipid peroxidation, and depleted the antioxidants. It also disturbed the synaptic neurotransmission by elevating the activities of acetylcholine esterase and monoamine oxidase resulting in the depletion of dopamine and serotonin and accumulation of glutamate and norepinephrine. Al also deteriorated the expression of genes involved in apoptosis and the production of amyloid-β plaques as well as phosphorylation of tau. The new bithiophene at the low dose reversed most of the previous deleterious effects of aluminum in the cerebral cortex and was in many instances superior to the reference drug; memantine.

CONCLUSION

Taking together, the bithiophene modulated the AD etiology through antioxidant activity, prevention of neuronal and synaptic loss, and probably mitigating the formation of amyloid-β plaques and phosphorylation of tau.

A responsive cascade drug delivery scaffold adapted to the therapeutic time window for peripheral nerve injury repair

Peripheral nerve injury (PNI) is a common clinical challenge, requiring timely and orderly initiation of synergistic anti-inflammatory and reparative therapy. Although the existing cascade drug delivery system can realize sequential drug release through regulation of the chemical structure of drug carriers, it is difficult to adjust the release kinetics of each drug based on the patient's condition. Therefore, there is an urgent need to develop a cascade drug delivery system that can dynamically adjust drug release and realize personalized treatment. Herein, we developed a responsive cascade drug delivery scaffold (RCDDS) which can adapt to the therapeutic time window, in which Vitamin B12 is used in early controllable release to suppress inflammation and nerve growth factor promotes regeneration by cascade loading. The RCDDS exhibited the ability to modulate the drug release kinetics by hierarchically opening polymer chains triggered by ultrasound, enabling real-time adjustment of the anti-inflammatory and neuroregenerative therapeutic time window depending on the patient's status. In the rat sciatic nerve injury model, the RCDDS group was able to achieve neural repair effects comparable to the autograft group in terms of tissue structure and motor function recovery. The development of the RCDDS provides a useful route toward an intelligent cascade drug delivery system for personalized therapy.

Modulatory Effect of Low-Intensity Transcranial Ultrasound Stimulation on Behaviour and Neural Oscillation in Mouse Models of Alzheimer's Disease

Transcranial ultrasound stimulation (TUS) is a noninvasive brain neuromodulation technique. The application of TUS for Alzheimer's disease (AD) therapy has not been widely studied. In this study, a long-term course (28 days) of TUS was used to stimulate the hippocampus of APP/PS1 mice. We examined the modulatory effect of TUS on behavior and neural oscillation in AD mice. We found that TUS can 1) improve the learning and memory abilities of AD mice; 2) reduce the phase-amplitude coupling of delta-epsilon, delta-gamma and theta-gamma frequency bands of local field potential, and increase the relative power of epsilon frequency bands in AD mice; 3) reduce the spike firing rate of interneurons and inhibit the phase-locked angle deflection between the theta frequency bands and the spikes of the two types of neurons that develops with the progression of the disease in AD mice. In summary, we demonstrate that TUS could effectively improve cognitive behavior and modulate neural oscillation with AD.

A Bibliometric Analysis for Low-Intensity Ultrasound Study Over the Past Three Decades

Low-intensity ultrasound (LI-US) is a non-invasive stimulation technique that has emerged in recent years and has been shown to have positive effects on neuromodulation, fracture healing, inflammation improvement, and metabolic regulation. This study reports the conclusions of a bibliometric analysis of LI-US. Input data for the period between 1995 and 2022, including 7209 related articles in the field of LI-US, were collected from the core library of the Web of Science (WOS) database. Using these data, a set of bibliometric indicators was obtained to gain knowledge on different aspects: global production, research areas, and sources analysis, contributions of countries and institutions, author analysis, citation analysis, and keyword analysis. This study combined the data analysis capabilities provided by the WOS database, making use of two bibliometric software tools: R software and VOS viewer to achieve analysis and data exploration visualization, and predicted the further development trends of LI-US. It turns out that the United States and China are co-leaders while Zhang ZG is the most significant author in LI-US. In the future, the hot spots of LI-US will continue to focus on parameter research, mechanism discussion, safety regulations, and neuromodulation applications.

Application of transcranial brain stimulation in dementia

The number of patients with dementia grows rapidly as the global population ages, which posits tremendous health-care burden to the society. Only cholinesterase inhibitors and a N-methyl-D-aspartate receptor antagonist have been approved for treating patients with Alzheimer's disease (AD), and their clinical effects remained limited. Medical devices serve as an alternative therapeutic approach to modulating neural activities and enhancing cognitive function. Four major brain stimulation technologies including deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and transcranial ultrasound stimulation (TUS) have been applied to AD in a clinical trial setting. DBS allows electrical stimulation at the specified nucleus but remains resource-demanding, and after all, an invasive surgery; whereas TMS and tDCS are widely available and affordable but less ideal with respect to localization. The unique physical property of TUS, on the other hand, allows both thermal and mechanical energy to be transduced and focused for neuromodulation. In the context of dementia, using focused ultrasound to induce blood-brain barrier opening for delivering drugs and metabolizing amyloid protein has drawn great attention in recent years. Furthermore, low-intensity pulsed ultrasound has demonstrated its neuroprotective effects in both in vitro and in vivo studies, leading to ongoing clinical trials for AD. The potential and limitation of transcranial brain stimulation for treating patients with dementia would be discussed in this review.

Low-intensity pulsed ultrasound ameliorates glia-mediated inflammation and neuronal damage in experimental intracerebral hemorrhage conditions

BACKGROUND

Intracerebral hemorrhage (ICH) is a condition associated with high morbidity and mortality, and glia-mediated inflammation is a major contributor to neurological deficits. However, there is currently no proven effective treatment for clinical ICH. Recently, low-intensity pulsed ultrasound (LIPUS), a non-invasive method, has shown potential for neuroprotection in neurodegenerative diseases. This study aimed to investigate the neuroprotective effects and potential mechanisms of LIPUS on glia-mediated inflammation in ICH.

METHODS

This study used 289 mice to investigate the effects of LIPUS on ICH. ICH was induced by injecting bacterial collagenase (type VII-S; 0.0375 U) into the striatum of the mice. LIPUS was applied noninvasively for 3 days, including a 2-h-delayed intervention to mimic clinical usage. The study evaluated neurological function, histology, brain water content, hemoglobin content, MRI, and protein expression of neurotrophic factors, inflammatory molecules, and apoptosis. In vitro studies investigated glia-mediated inflammation by adding thrombin (10 U/mL) or conditioned media to primary and cell line cultures. The PI3K inhibitor LY294002 was used to confirm the effects of PI3K/Akt signaling after LIPUS treatment.

RESULTS

LIPUS treatment improved neurological deficits and reduced tissue loss, edema, and neurodegeneration after ICH. The protective effects of LIPUS resulted from decreased glia-mediated inflammation by inhibiting PI3K/Akt-NF-κB signaling, which reduced cytokine expression and attenuated microglial activation-induced neuronal damage in vitro.

CONCLUSIONS

LIPUS treatment improved neurological outcomes and reduced glia-mediated inflammation by inhibiting PI3K/Akt-NF-κB signaling after ICH. LIPUS may provide a non-invasive potential management strategy for ICH.

Ameliorative Effect of Palm Oil in Aluminum Lactate Induced Biochemical and Histological Implications in Rat Brain

α-Tocotrienol is one of the major constituents of palm oil. It is a well-known antioxidant and cholesterol-lowering neuroprotectant. To prevent the initiation of Alzheimer's like symptoms, much attention has been shifted to the major role played by antioxidants. Previous epidemiological reports correlate the increasing incidence of developing Alzheimer's disease (AD), to the aluminum (Al) content in drinking water. Al, being a ubiquitous element, has a long history of being particularly reactive towards multiple aspects of neurobiology. So, the current study examines the effect of Al-induced behavioral, biochemical, and histopathological changes in rat brain; and the ameliorative effect of palm oil in reducing the resulting neurotoxicity. The experimental design consisted of 4 groups: control group which received rodent chow diet and water ad libitum; Al group received aluminum lactate (50 mg/kg bw); Al + palm oil group was administered with Al (50 mg/kg bw) and palm oil (60 mg/kg bw); and palm oil group received palm oil (60 mg/kg bw). Al was given by oral gavage once daily for 6 weeks and palm oil was administered intraperitoneally. After 6 weeks of supplementation, Al + palm oil group showed significantly lower malondialdehyde (MDA) content, but higher superoxide dismutase (SOD), catalase (CAT), GST, and GPx activity as compared to Al group. Al group has significantly higher level of MDA content, but lower SOD, CAT, GST, and GPx activity as compared to control group. In conclusion, this study suggested that palm oil was effective in preventing the Al-induced brain damage in rats.

Leflunomide abrogates neuroinflammatory changes in a rat model of Alzheimer's disease: the role of TNF-α/NF-κB/IL-1β axis inhibition

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is associated with disrupted cognition and behavior. Neuroinflammatory pathogenesis is the main component that contributes to AD initiation and progression through microglial activation and neuronal damage. Thus, targeting inflammatory pathways may help manage AD. In this study, for the first time, the potential prophylactic and therapeutic effects of leflunomide were investigated either alone or in combination with rivastigmine in aluminum chloride (AlCl₃)-induced AD-like rats using behavioral, biochemical, and histological approaches. Thirty-six adult male albino rats were divided into two protocols: the treatment protocol, subdivided into five groups (n = 6)-(1) control group, (2) AlCl₃ (50, 70, 100 mg/kg/I.P) group, (3) reference group (rivastigmine 2 mg/kg/P.O.), (4) experimental group (leflunomide 10 mg/kg/P.O.), and (5) combination group (rivastigmine + leflunomide); and the prophylactic protocol (leflunomide 10 mg/kg/P.O.), which started 2 weeks before AlCl₃ induction. The results showed that AlCl₃ disrupted learning and memory parameters in rats and increased amyloid-β plaque deposition and neurofibrillary tangle aggregation. Moreover, AlCl₃ administration markedly elevated acetylcholinesterase activity, nuclear factor-kappa β, tumor necrosis factor-α, and interleukin-1 beta, and marked degenerative changes in the pyramidal neurons. However, administration of leflunomide alone or with rivastigmine in AlCl₃-induced AD rats restored most of the behavioral, biochemical, and histological parameters triggered by AlCl₃ in rats. Our findings suggest that leflunomide can potentially restore most of the neuronal damage in the hippocampal tissues of AlCl₃-induced AD rats. However, these preclinical findings still need to be confirmed in clinical trials.

Magnetization transfer ratio for assessing remyelination after transcranial ultrasound stimulation in the lysolecithin rat model of multiple sclerosis

It has been shown that transcranial ultrasound stimulation (TUS) is capable of attenuating myelin loss and providing neuroprotection in animal models of brain disorders. In this study, we investigated the ability of TUS to promote remyelination in the lysolecithin (LPC)-induced local demyelination in the hippocampus. Demyelination was induced by the micro-injection of 1.5 μL LPC (1%) into the rat hippocampus and the treated group received daily TUS for 5 or 12 days. Magnetic resonance imaging techniques, including magnetization transfer ratio (MTR) and T2-weighted imaging, were used to longitudinally characterize the demyelination model. Furthermore, the therapeutic effects of TUS on LPC-induced demyelination were assessed by Luxol fast blue (LFB) staining. Our data revealed that reductions in MTR values observed during demyelination recover almost completely upon remyelination. The MTR values in demyelinated lesions were significantly higher in TUS-treated rats than in the LPC-only group after undergoing TUS. Form histological observation, TUS significantly reduced the size of demyelinated lesion 7 days after LPC administration. This study demonstrated that MTR was a sensitive and reproducible quantitative marker to assess remyelination process in vivo during TUS treatment. These findings might open new promising treatment strategies for demyelinating diseases such as multiple sclerosis.

The Effects of Transcranial Focused Ultrasound Stimulation of Nucleus Accumbens on Neuronal Gene Expression and Brain Tissue in High Alcohol-Preferring Rats

We investigated the effect of low-intensity focused ultrasound (LIFU) on gene expression related to alcohol dependence and histological effects on brain tissue. We also aimed at determining the miRNA-mRNA relationship and their pathways in alcohol dependence-induced expression changes after focused ultrasound therapy. We designed a case-control study for 100 days of observation to investigate differences in gene expression in the short-term stimulation group (STS) and long-term stimulation group (LTS) compared with the control sham group (SG). The study was performed in our Experimental Research Laboratory. 24 male high alcohol-preferring rats 63 to 79 days old, weighing 270 to 300 g, were included in the experiment. LTS received 50-day LIFU and STS received 10-day LIFU and 40-day sham stimulation, while the SG received 50-day sham stimulation. In miRNA expression analysis, it was found that LIFU caused gene expression differences in NAc. Significant differences were found between the groups for gene expression. Compared to the SG, the expression of 454 genes in the NAc region was changed in the STS while the expression of 382 genes was changed in the LTS. In the LTS, the expression of 32 genes was changed in total compared to STS. Our data suggest that LIFU targeted on NAc may assist in the treatment of alcohol dependence, especially in the long term possibly through altering gene expression. Our immunohistochemical studies verified that LIFU does not cause any tissue damage. These findings may lead to new studies in investigating the efficacy of LIFU for the treatment of alcohol dependence and also for other psychiatric disorders.

Simultaneous multi-target ultrasound neuromodulation in freely-moving mice based on a single-element ultrasound transducer

Objective.Ultrasound neuromodulation has become an emerging method for the therapy of neurodegenerative and psychiatric diseases. The phased array ultrasonic transducer enables multi-target ultrasound neuromodulation in small animals, but the relatively large size and mass and the thick cables of the array limit the free movement of small animals. Furthermore, spatial interference may occur during multi-target ultrasound brain stimulation with multiple micro transducers.Approach.In this study, we developed a miniature power ultrasound transducer and used the virtual source time inversion method and 3D printing technology to design, optimize, and manufacture the acoustic holographic lens to construct a multi-target ultrasound neuromodulation system for free-moving mice. The feasibility of the system was verified byin vitrotranscranial ultrasound field measurements,in vivodual-target blood-brain barrier (BBB) opening experiments, andin vivodual-target ultrasound neuromodulation experiments.Main results.The developed miniature transducer had a diameter of 4.0 mm, a center frequency of 1.1 MHz, and a weight of 1.25 g. The developed miniature acoustic holographic lens had a weight of 0.019 g to generate dual-focus transcranial ultrasound. The ultrasonic field measurements' results showed that the bifocal's horizontal distance was 3.0 mm, the -6 dB focal spot width in thex-direction was 2.5 and 2.25 mm, and 2.12 and 2.24 mm in they-direction. Finally, thein vivoexperimental results showed that the system could achieve dual-target BBB opening and ultrasound neuromodulation in freely-moving mice.Significance.The ultrasonic neuromodulation system based on a miniature single-element transducer and the miniature acoustic holographic lens could achieve dual-target neuromodulation in awake small animals, which is expected to be applied to the research of non-invasive dual-target ultrasonic treatment of brain diseases in awake small animals.

Modulation effect of non-invasive transcranial ultrasound stimulation in an ADHD rat model

Objective.Previous studies have demonstrated that transcranial ultrasound stimulation (TUS) with noninvasive high penetration and high spatial resolution has an effective neuromodulatory effect on neurological diseases. Attention deficit hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder that severely affects child health. However, the neuromodulatory effects of TUS on ADHD have not been reported to date. This study aimed to investigate the neuromodulatory effects of TUS on ADHD.Approach.TUS was performed in ADHD model rats for two consecutive weeks, and the behavioral improvement of ADHD, neural activity of ADHD from neurons and neural oscillation levels, and the plasma membrane dopamine transporter and brain-derived neurotrophic factor (BDNF) in the brains of ADHD rats were evaluated.Main results.TUS can improve cognitive behavior in ADHD rats, and TUS altered neuronal firing patterns and modulated the relative power and sample entropy of local field potentials in the ADHD rats. In addition, TUS can also enhance BDNF expression in the brain tissues.Significance. TUS has an effective neuromodulatory effect on ADHD and thus has the potential to clinically improve cognitive dysfunction in ADHD.

Low intensity focused ultrasound: a new prospect for the treatment of Parkinson's disease

Background: As a chronic and progressive neurodegenerative disease, Parkinson's disease (PD) still lacks effective and safe targeted drug therapy. Low-intensity focused ultrasound (LIFU), a new method to stimulate the brain and open the blood-brain barrier (BBB), has been widely concerned by PD researchers due to its non-invasive characteristics.Methods: PubMed was searched for the past 10 years using the terms 'focused ultrasound', 'transcranial ultrasound', 'pulse ultrasound', and 'Parkinson's disease'. Relevant citations were selected from the authors' references. After excluding articles describing high-intensity focused ultrasound or non-Parkinson's disease applications, we found more than 100 full-text analyses for pooled analysis.Results: Current preclinical studies have shown that LIFU could improve PD motor symptoms by regulating microglia activation, increasing neurotrophic factors, reducing oxidative stress, and promoting nerve repair and regeneration, while LIFU combined with microbubbles (MBs) can promote drugs to cross the BBB, which may become a new direction of PD treatment. Therefore, finding an efficient drug carrier system is the top priority of applying LIFU with MBs to deliver drugs.Conclusions: This article aims to review neuro-modulatory effect of LIFU and the possible biophysical mechanism in the treatment of PD, summarize the latest progress in delivering vehicles with MBs, and discuss its advantages and limitations.

Disease-Modifying Effects of Non-Invasive Electroceuticals on β-Amyloid Plaques and Tau Tangles for Alzheimer's Disease

Electroceuticals refer to various forms of electronic neurostimulators used for therapy. Interdisciplinary advances in medical engineering and science have led to the development of the electroceutical approach, which involves therapeutic agents that specifically target neural circuits, to realize precision therapy for Alzheimer's disease (AD). To date, extensive studies have attempted to elucidate the disease-modifying effects of electroceuticals on areas in the brain of a patient with AD by the use of various physical stimuli, including electric, magnetic, and electromagnetic waves as well as ultrasound. Herein, we review non-invasive stimulatory systems and their effects on β-amyloid plaques and tau tangles, which are pathological molecular markers of AD. Therefore, this review will aid in better understanding the recent technological developments, applicable methods, and therapeutic effects of electronic stimulatory systems, including transcranial direct current stimulation, 40-Hz gamma oscillations, transcranial magnetic stimulation, electromagnetic field stimulation, infrared light stimulation and ionizing radiation therapy, and focused ultrasound for AD.

Modulation effect of low-intensity transcranial ultrasound stimulation on REM and NREM sleep

Previous studies have shown that modulating neural activity can affect rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Low-intensity transcranial ultrasound stimulation (TUS) can effectively modulate neural activity. However, the modulation effect of TUS on REM and NREM sleep is still unclear. In this study, we used ultrasound to stimulate motor cortex and hippocampus, respectively, and found the following: (i) In healthy mice, TUS increased the NREM sleep ratio and decreased the REM sleep ratio, and altered the relative power and sample entropy of the delta band and spindle in NREM sleep and that of the theta and gamma bands in REM sleep. (ii) In sleep-deprived mice, TUS decreased the ratio of REM sleep or the relative power of the theta band during REM sleep. (iii) In sleep-disordered Alzheimer’s disease (AD) mice, TUS increased the total sleep time and the ratio of NREM sleep and modulated the relative power and the sample entropy of the delta and spindle bands during NREM and that of the theta band during REM sleep. These results demonstrated that TUS can effectively modulate REM and NREM sleep and that modulation effect depends on the sleep state of the samples, and can improve sleep in sleep-disordered AD mice.

Ultrasound Neuromodulation Reduces Demyelination in a Rat Model of Multiple Sclerosis

Microglia, astrocytes, and oligodendrocyte progenitor cells (OPCs) may serve as targets for remyelination-enhancing therapy. Low-intensity pulsed ultrasound (LIPUS) has been demonstrated to ameliorate myelin loss and inhibit neuroinflammation in animal models of brain disorders; however, the underlying mechanisms through which LIPUS stimulates remyelination and glial activation are not well-understood. This study explored the impacts of LIPUS on remyelination and resident cells following lysolecithin (LPC)-induced local demyelination in the hippocampus. Demyelination was induced by the micro-injection of 1.5 μL of 1% LPC into the rat hippocampus, and the treatment groups received daily LIPUS stimulation for 5 days. The therapeutic effects of LIPUS on LPC-induced demyelination were assessed through immunohistochemistry staining. The staining was performed to evaluate remyelination and Iba-1 staining as a microglia marker. Our data revealed that LIPUS significantly increased myelin basic protein (MBP) expression. Moreover, the IHC results showed that LIPUS significantly inhibited glial cell activation, enhanced mature oligodendrocyte density, and promoted brain-derived neurotrophic factor (BDNF) expression at the lesion site. In addition, a heterologous population of microglia with various morphologies can be found in the demyelination lesion after LIPUS treatment. These data show that LIPUS stimulation may serve as a potential treatment for accelerating remyelination through the attenuation of glial activation and the enhancement of mature oligodendrocyte density and BDNF production.

Preventive and Therapeutic Effects of Low-Intensity Ultrasound Stimulation on Migraine in Rats

This study sought to systematically evaluate the prophylactic and therapeutic effects of low-intensity transcranial ultrasound stimulation on migraine in rats. We used video recordings to assess the head scratching behavior and laser speckle contrast imaging to record the changes in cerebral blood flow velocity of freely moving rats in a healthy group, migraine group, migraine group with ultrasound prevention, and migraine group with ultrasound therapy. Results demonstrated that (1) head scratching during migraine attacks in rats was accompanied by an decrease in cerebral blood flow; (2) both ultrasound prevention and therapy significantly reduced the number of head scratches but did not reduce the cerebral blood flow velocity; and (3) the number of head scratches in the ultrasound stimulation groups was not affected by the auditory effect. These results reveal that low-intensity ultrasound has the potential to be used clinically in the prevention and therapeutic treatment of migraine.

Stable Cavitation Interferes with Aβ16-22 Oligomerization

Ultrasound and microbubbles are used for many medical applications nowadays. Scanning ultrasound can remove amyloid-β (Aβ) aggregates in the mouse brain and restores memory in an Alzheimer's disease mouse model. In vitro studies showed that amyloid fibrils are fragmented due to the ultrasound-induced bubble inertial cavitation, and ultrasonic pulses accelerate the depolymerization of Aβ fibrils into monomers at 1 μM of concentration. Under applied ultrasound, microbubbles can be in a stable oscillating state or unstable inertial cavitation state. The latter occurs when ultrasound causes a dramatic change of bubble sizes above a certain acoustic pressure. We have developed and implemented a nonequilibrium molecular dynamics simulation algorithm to the AMBER package, to facilitate the investigation of the molecular mechanism of Aβ oligomerization under stable cavitation. Our results indicated that stable cavitation not only inhibited oligomeric formation, but also prevented the formation of β-rich oligomers. The network analysis of state transitions revealed that stable cavitation altered the oligomerization pathways of Aβ_16-22 peptides. Our simulation tool may be applied to optimize the experimental conditions to achieve the best therapeutical effect.

Noninvasive Low-Intensity Focused Ultrasound Mediates Tissue Protection following Ischemic Stroke

Objective and Impact Statement. This study examined the efficacy and safety of pulsed, low-intensity focused ultrasound (LIFU) and determined its ability to provide neuroprotection in a murine permanent middle cerebral artery occlusion (pMCAO) model. Introduction. Focused ultrasound (FUS) has emerged as a new therapeutic strategy for the treatment of ischemic stroke; however, its nonthrombolytic properties remain ill-defined. Therefore, we examined how LIFU influenced neuroprotection and vascular changes following stroke. Due to the critical role of leptomeningeal anastomoses or pial collateral vessels, in cerebral blood flow restoration and tissue protection following ischemic stroke, we also investigated their growth and remodeling. Methods. Mice were exposed to transcranial LIFU (fundamental frequency: 1.1 MHz, sonication duration: 300 ms, interstimulus interval: 3 s, pulse repetition frequency: 1 kHz, duty cycle per pulse: 50%, and peak negative pressure: -2.0 MPa) for 30 minutes following induction of pMCAO and then evaluated for infarct volume, blood-brain barrier (BBB) disruption, and pial collateral remodeling at 24 hrs post-pMCAO. Results. We found significant neuroprotection in mice exposed to LIFU compared to mock treatment. These findings correlated with a reduced area of IgG deposition in the cerebral cortex, suggesting attenuation of BBB breakdown under LIFU conditions. We also observed increased diameter of CD31-postive microvessels in the ischemic cortex. We observed no significant difference in pial collateral vessel size between FUS and mock treatment at 24 hrs post-pMCAO. Conclusion. Our data suggests that therapeutic use of LIFU may induce protection through microvascular remodeling that is not related to its thrombolytic activity.

The Value of First-Order Features Based on the Apparent Diffusion Coefficient Map in Evaluating the Therapeutic Effect of Low-Intensity Pulsed Ultrasound for Acute Traumatic Brain Injury With a Rat Model

Purpose

In order to evaluate the neuroprotective effect of low-intensity pulsed ultrasound (LIPUS) for acute traumatic brain injury (TBI), we studied the potential of apparent diffusion coefficient (ADC) values and ADC-derived first-order features regarding this problem.

Methods

Forty-five male Sprague Dawley rats (sham group: 15, TBI group: 15, LIPUS treated: 15) were enrolled and underwent magnetic resonance imaging. Scanning layers were acquired using a multi-shot readout segmentation of long variable echo trains (RESOLVE) to decrease distortion. The ultrasound transducer was applied to the designated region in the injured cortical areas using a conical collimator and was filled with an ultrasound coupling gel. Regions of interest were manually delineated in the center of the damaged cortex on the diffusion weighted images (b = 800 s/mm²) layer by layer for the TBI and LIPUS treated groups using the open-source software ITK-SNAP. Before analysis and modeling, the features were normalized using a z-score method, and a logistic regression model with a backward filtering method was employed to perform the modeling. The entire process was completed using the R language.

Results

During the observation time, the ADC values ipsilateral to the trauma in the TBI and LIPUS groups increased rapidly up to 24 h. After statistical analysis, the 10th percentile, 90th percentile, mean, skewness, and uniformity demonstrated a significant difference among three groups. The receiver operating characteristic curve (ROC) analysis shows that the combined LR model exhibited the highest area under the curve value (AUC: 0.96).

Conclusion

The combined LR model of first-order features based on the ADC map can acquire a higher diagnostic performance than each feature only in evaluating the neuroprotective effect of LIPUS for TBI. Models based on first-order features may have potential value in predicting the therapeutic effect of LIPUS in clinical practice in the future.

Transcranial Ultrasound Stimulation Reverses Behavior Changes and the Expression of Calcium-Binding Protein in a Rodent Model of Schizophrenia

Cognitive dysfunctions are a core feature of schizophrenia that may be linked to abnormalities in gamma-aminobutyric-acid (GABA)ergic neurons. Traditional antipsychotics show poor efficacy in treating cognitive symptoms. The purpose of this study was to investigate the restorative role of transcranial ultrasound stimulation (TUS) in counteracting dizocilpine (MK-801)-induced cognitive deficits and GABAergic interneuron dysfunction in a simulation of schizophrenia. Some rats subjected to MK-801 administration were treated with low-intensity pulsed ultrasound (LIPUS) daily for 5 days, while other rats subjected to MK-801 administration received no LIPUS treatment. After LIPUS treatment, the neuroprotective effects of LIPUS in the LIPUS-treated rats were assessed through behavioral analysis, western blotting, and histological observations. Compared with the MK-801-treated group, the MK-801 plus LIPUS-treated rats revealed a preference for novel objects. The MK-801 plus LIPUS-treated rats also exhibited a significant decrease in swim times compared to the MK-801-treated rats. LIPUS stimulation significantly increased hippocampal levels of CB and PV and restored the cell densities of PV + and CB + in the cingulate cortex in the MK-801 plus LIPUS-treated group. In addition, LIPUS stimulation rebalanced the BDNF levels in the hippocampus and medial prefrontal cortex. Our findings indicate that LIPUS improves cognitive deficits and ameliorates neuropathology in MK-801-treated rats. These results suggest that LIPUS may constitute a potential novel therapeutic approach for the treatment of schizophrenia.

Anti-inflammatory and Neuroprotective Effects of Transcranial Ultrasound Stimulation on Parkinson's Disease

Low-intensity pulsed ultrasound (LIPUS) is a promising non-invasive neuromodulation tool for deep brain stimulation. Here, we investigated the impact of LIPUS, including neuroprotective effects, on the pathology of Parkinson's disease (PD) in an animal model. Sprague-Dawley rats were injected with 6-hydroxydopamine (6-OHDA) at two sites in the right striatum. LIPUS (1 MHz, 5% duty cycle, 1-Hz pulse repetition frequency, 15 min/d) stimulation was then applied to some of the rats (the 6-OHDA + LIPUS group) beginning 2 wk after the 6-OHDA administration, while the remaining rats (the 6-OHDA group) received no LIPUS stimulation. The 6-OHDA-induced inflammatory responses and expressions of neurotrophic factors were quantified with immunofluorescence activity. The safety of LIPUS was assessed using hematoxylin and eosin and Nissl staining. LIPUS treatment significantly inhibited 6-OHDA-induced glial activation and the phosphorylation of nuclear factor-κB p65 in the substantia nigra pars compacta. Further study revealed that LIPUS effectively preserved the levels of neurotrophic factors, dopamine transporter and tight junction proteins of the blood-brain barrier in the 6-OHDA + LIPUS group compared with the 6-OHDA group. These results indicate that LIPUS acts via multiple neuroprotective mechanisms in the PD rat model and suggest that LIPUS can be viewed as a potential treatment for PD.

Review of Noninvasive or Minimally Invasive Deep Brain Stimulation

Brain stimulation is a critical technique in neuroscience research and clinical application. Traditional transcranial brain stimulation techniques, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS) have been widely investigated in neuroscience for decades. However, TMS and tDCS have poor spatial resolution and penetration depth, and DBS requires electrode implantation in deep brain structures. These disadvantages have limited the clinical applications of these techniques. Owing to developments in science and technology, substantial advances in noninvasive and precise deep stimulation have been achieved by neuromodulation studies. Second-generation brain stimulation techniques that mainly rely on acoustic, electronic, optical, and magnetic signals, such as focused ultrasound, temporal interference, near-infrared optogenetic, and nanomaterial-enabled magnetic stimulation, offer great prospects for neuromodulation. This review summarized the mechanisms, development, applications, and strengths of these techniques and the prospects and challenges in their development. We believe that these second-generation brain stimulation techniques pave the way for brain disorder therapy.

Focused ultrasound: Innovation in use for neurologic conditions

Focused ultrasound has emerged as a key tool for neurologic disorders. In this focused review, we discuss the utility in disrupting the blood brain barrier to maximize treatment. This can facilitate creating direct coagulative lesions and aid in the administration of chemotherapy. Furthermore, it can facilitate neuromodulation when used in pulse sequencing. The current literature regarding brain tumors, essential tremor, and obsessive-compulsive disorder is reviewed. Additionally, concepts and experimental outcomes for neurodegenerative disease such as Alzheimer's is presented. Focused ultrasound as a tool is still in its infancy but the potential for adjuvant and direct therapy is promising. More clinical uses will become apparent in coming decades.