Stimulation Techniques Research Articles

Small extracellular vesicles derived from sequential stimulation of canine adipose-derived mesenchymal stem cells enhance anti-inflammatory activity

BackgroundSmall extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) are recognized for their therapeutic potential in immune modulation and tissue repair, especially in veterinary medicine. This study introduces an innovative sequential stimulation (IVES) technique, involving low-oxygen gas mixture preconditioning using in vitro fertilization gas (IVFG) and direct current electrical stimulation (ES20), to enhance the anti-inflammatory properties of sEVs from canine adipose-derived MSCs (cAD-MSCs). Initial steps involved isolation and comprehensive characterization of cAD-MSCs, including morphology, gene expression, and differentiation potentials, alongside validation of the electrical stimulation protocol. IVFG, ES20, and IVES were applied simultaneously with a control condition. Stimulated cAD-MSCs were evaluated for morphological changes, cell viability, and gene expressions. Conditioned media were collected and purified for sEV isolation on Day1, Day2, and Day3. To validate the efficacy of IVES for sEV production, various analyses were conducted, including microscopic examination, surface marker assessment, zeta-potential measurement, protein quantification, nanoparticle tracking analysis, and determination of anti-inflammatory activity.ResultsWe found that IVES demonstrated non-cytotoxicity and induced crucial genotypic changes associated with sEV production in cAD-MSCs. Interestingly, IVFG influenced cellular adaptation, while ES20 induced hypoxia activation. By merging these stimulations, IVES enhanced sEV stability and quality profiles. The cAD-MSC-derived sEVs exhibited anti-inflammatory activity in lipopolysaccharide-induced RAW264.7 macrophages, emphasizing their improved effectiveness without cytotoxicity or immunogenicity. These effects were consistent across day 3 collection, indicating the establishment of an effective protocol for sEV production.ConclusionsThis research established an innovative sequential stimulation method with positive impact on sEV characteristics including stability, quality, and anti-inflammatory activity. This study not only contributes to the enhancement of sEV production but also sheds light on their functional aspects for therapeutic interventions.

DeepFocus: a transnasal approach for optimized deep brain stimulation of reward circuit nodes.

Transcranial electrical stimulation (TES) is an effective technique to modulate brain activity and treat diseases. However, TES is primarily used to stimulate superficial brain regions and is unable to reach deeper targets. The spread of injected currents in the head is affected by volume conduction and the additional spreading of currents as they move through head layers with different conductivities, as is discussed in [1]. In this paper, we introduce DeepFocus, a technique aimed at stimulating deep brain structures in the brain's "reward circuit" (e.g. the orbitofrontal cortex, Brodmann area 25, amygdala, etc.). To accomplish this, DeepFocus utilizes transnasal electrode placement (under the cribriform plate and within the sphenoid sinus) in addition to electrodes placed on the scalp, and optimizes current injection patterns across these electrodes. To quantify the benefit of DeepFocus, we develop the DeepROAST simulation and optimization platform. DeepROAST simulates the effect of complex skull-base bones' geometries on the electric fields generated by DeepFocus configurations using realistic head models. It also uses optimization methods to search for focal and efficient current injection patterns, which we use in our simulation and cadaver studies. In simulations, optimized DeepFocus patterns created larger and more focal fields in several regions of interest than scalp-only electrodes. In cadaver studies, DeepFocus patterns created large fields at the medial orbitofrontal cortex (OFC) with magnitudes comparable to stimulation studies, and, in conjunction with established cortical stimulation thresholds, suggest that the field intensity is sufficient to create neural response, e.g. at the OFC. This minimally invasive stimulation technique can enable more efficient and less risky targeting of deep brain structures to treat multiple neural conditions.&#xD.

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

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

Non-invasive brain stimulation in cognitive sciences and Alzheimer's disease

Over the last four decades, non-invasive brain stimulation techniques (NIBS) have significantly gained interest in the fields of cognitive sciences and dementia care, including neurorehabilitation, for its emerging potential in increasing the insights over brain functions and in boosting residual cognitive functions. In the present paper, basic physiological and technical mechanisms and different applications of NIBS were reviewed and discussed to highlight the importance of NIBS in multidisciplinary and translational approaches in clinical and research settings of cognitive sciences and neurodegenerative diseases, especially in Alzheimer's disease. Indeed, NIBS strategies may represent a promising opportunity to increase the potential of neuromodulation as efficacious interventions for individualized patients care.

Respiratory muscle training in people with cervical spinal cord injury - A systematic review.

Spinal cord injury is a physiological disruption often caused by trauma, leading to severe physical and psychological effects, including irreversible impairment and disability. Cervical injuries, particularly between C1 and C8, are the most severe, potentially causing diaphragm paralysis and requiring mechanical ventilation. Reduced respiratory muscle strength not only affects respiratory function but also significantly impacts voice, speech, and communication, which are crucial for quality of life. Conduct a systematic review of the literature on respiratory muscle training protocols in individuals with cervical spinal cord injury and evaluate the methodological quality of scientific publications. Studies were searched by two independent researchers in the Regional Portal of the Virtual Health Library, EMBASE, SCOPUS and PubMed databases, using the descriptors: "respiratory muscle strength", "breathing training", and "cervical spinal cord injury", with no restriction on the time of publication. Studies containing respiratory muscle strength measurements and respiratory muscle training in people with cervical SCI were included and those that associated other techniques with functional respiratory training, such as electrical stimulation and other complementary techniques were excluded. The studies had the methodological quality (internal and external validity) classified by the PEDro scale (Physiotherapy Evidence Database). Nine studies were identified and considered valid based on the inclusion criteria. The protocols presented varied parameters. The session time ranged from 15 to 45 minutes, the number of sessions per day ranged from 1 to 2, the number of days per week ranged from 3 to 7, and the number of intervention weeks ranged from 4 to 10. Only three studies presented internal and external validity for respiratory muscle training programs. This review identified that respiratory muscle training is an effective intervention to improve respiratory function in people with cervical SCI. However, due to the poor methodological quality of the studies, the effect size of the treatment, as well as the ideal dose and intensity, requires further investigation to better determine its overall effectiveness.

Transcranial electrical evoked muscle potentials for pediatric neurosurgery: scoping review of stimulation techniques and success rates.

The background of this scoping review is that pediatric neurosurgery in the vicinity of motor pathways is associated with the risk of motor tract damage. By measuring transcranial electrical evoked potentials in muscles (electromyogram) or from the spinal cord (epidural D-wave) functional disorders and impending damage can be detected during surgery and countermeasures can be initiated. The objective was to summarize stimulation techniques of transcranial electrical stimulation and the success rate of motor evoked potentials exclusively in children undergoing neurosurgery. The data source was a literature search for reports meeting the suitability criteria (original articles and case series including motor evoked potentials and pediatric neurosurgery). Twenty-four articles meeting suitability criteria were retrieved. The most common primary electrode positions for electrical stimulation were at C3 vs. C4 and C1 vs. C2 according to the 10-20-system of EEG. Single trains of 1 to 9 pulses with voltages from 160 to 900V and pulse durations from 50 to 500µs were applied for voltage-controlled stimulation. Interstimulus intervals ranged from 0.1 to 9.9ms. Signals were filtered with high-pass filters between 1.5 and 300Hz and low-pass filters between 500 and 5000Hz. The overall rate of successful stimulation and measurement was 90.5% (N = 769). A broad range of stimulation parameters was used for transcranial electrical evoked potentials. Measurable potentials were obtained in most patients. Consideration of safety precautions is an important implication to avoid adverse events by application of high voltage to the motor cortex.

Transcranial direct current stimulation for patients with walking difficulties caused by cerebral small vessel disease: a randomized controlled study.

Cerebral small vessel disease (CSVD) is a chronic systemic degenerative disease affecting small blood vessels in the brain, leading to cognitive impairments. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that applies low electrical currents to the scalp, shows promise in treating cognitive and movement disorders. However, further clinical evaluation is required to assess the long-term effects of tDCS on neuroplasticity and gait in patients with CSVD. We investigated the effects of long-term, repeated tDCS on local brain perfusion, network connectivity, cognition, and gait in patients with CSVD and gait disorders (CSVD-GD). This prospective, single-blind, multicenter, randomized controlled study enrolled 66 patients with CSVD-GD, categorized into the tDCS and Sham groups. Imaging and gait characteristic data were collected over three periods using magnetic resonance imaging and a gait analyzer, along with neuropsychological assessments. Among 156 volunteers with CSVD-GD, 66 participated in this study, with 60 completing the entire process. Compared to the Sham group, the tDCS group exhibited a more pronounced increase in the cerebral blood flow to the dural cerebrospinal fluid ratio in regions such as the orbitofrontal cortex and cingulate gyrus (P < 0.05, FDR corrected), along with significantly greater improvements in gait speed and stride length. Tolerance to tDCS was good, with no difference in adverse reactions between the groups, except for a scalp burning sensation reported during the 1st week (24.24% and 6.06% in the tDCS and Sham groups, respectively; P = 0.003). Long-term tDCS is effective and safe for improving neuroplasticity and gait cognition in patients with CSVD.

Reactivation and consolidation of memory traces during post-encoding rest across the adult lifespan.

Episodic memory is a critical cognitive function that enables the encoding, storage, and retrieval of new information. Memory consolidation, a key stage of episodic memory, stabilizes this newly encoded information into long-lasting brain "storage." Studies using fMRI to investigate post-encoding awake rest holds promise to shed light on early, immediate consolidation mechanisms. Here, we review fMRI studies during episodic memory to document common methods to investigate post-encoding consolidation, such as multivoxel pattern analysis (MVPA) and functional connectivity, and the current state of the science in both healthy younger and older adults. In young adults, post-encoding reactivation of stimuli-specific neural patterns in the hippocampus and its connectivity with cortical and subcortical areas (e.g., visual-temporal cortex, medial prefrontal, and medial parietal cortex) correlate with subsequent memory performance. Conversely, studies in older adults highlight the importance of large-scale brain networks during post-encoding rest, particularly the default mode network (DMN). Alterations in connectivity between the DMN and task-positive networks may help older adults maintain episodic memory. Furthermore, non-invasive brain stimulation techniques can enhance these post-encoding consolidation processes and improve memory performance in both younger and older adults. Notably, a lack of studies has investigated post-encoding memory consolidation in neurodegenerative disorders. This review underscores the importance of understanding how post-encoding neural reactivation and connectivity evolve with age to partially explain age-related declines in episodic memory performance and how such declines can be restored.

Less is more - Retrospective analysis of the two-incision implantation technique for hypoglossal nerve stimulation and comparison of respiratory sensing lead curves against the three-incision technique.

Breathing-synchronized hypoglossal-nerve stimulation is a treatment option for suitable patients with severe obstructive-sleep-apnoea. The classical implantation technique requires three incisions: submental to place the stimulating-electrode on terminal branches of the hypoglossal-nerve, sub-clavicular to place the impulse generator, and on the lateral chest-wall to place a breathing-sensor lead. A two-incision-technique has been propagated and widely adopted whereby the respiratory-sensing-lead is placed deeper to the IPG-pocket. Our department switched to the 2-incision-technique in May 2021 and we set out to compare the two methods concerning the generated respiratory-sensing-curves. Cases operated between October 2020 and September 2022 were included. Parameters included age, gender, BMI, OR time, positioning of the detection-lead, and preoperative Apnoea-Hypopnoea Index (AHI). The generated respiratory-sensing curves were categorized by an independent expert blinded to the surgical-technique regarding conduciveness to optimal stimulation. 21 patients were included. 5 were operated with the 3-incision-technique. Women were underrepresented. There were no further significant differences in patient characteristics. The expert-opinion on the respiratory-sensing-curves did not vary between groups. Mean OR-time was marginally less in the 2-incision group without being statistically significant. The 2-incision-technique generates respiratory-sensing curves at par with those generated with 3-incision-implants. The limited patient data collected in this analysis suggests that OR-time can be reduced using the 2-incision-technique. There were no cases of postoperative complications in our cohort. It can be postulated that a 2-incision-implant has a lower risk of infection due to the reduced wound-surface.

The effects of bilateral M1 anodal tDCS on corticomotor excitability and acquisition the of a bimanual videogame skill.

Most activities of daily life involve some degree of coordinated, bimanual activity from the upper limbs. However, compared to single-handed movements, bimanual movements are processed, learned, and controlled from both hemispheres of the brain. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that enhances motor learning by modulating the activity of movement-associated brain regions. While effective in simple, single-handed tasks, tDCS has shown mixed results in complex bimanual tasks. This study investigated the effects of bilateral M1 anodal tDCS (biM1 a-tDCS) on learning and cortical excitability during a customized, bimanual racing videogame task. Thirty-six right-handed adults completed three lab visits (∼48h apart), practicing the task while receiving either biM1 a-tDCS or SHAM tDCS. Cortical excitability was measured with transcranial magnetic stimulation (TMS) and electromyography (EMG) before and after the first visit. Though all subjects demonstrated improvements over the course of the study, our analyses revealed significantly faster rates of learning on days 1 & 2, but not day 3, of practice in subjects receiving biM1 a-tDCS. Moreover, perhaps due to differences in baseline gaming experience and aptitude, this effect appeared to be stronger in female subjects. Interestingly, no significant differences in corticomotor excitability were observed between conditions. Though biM1 a-tDCS did not appear to impact corticomotor excitability, our results contribute to the growing body of evidence which seems to suggest that multifocal tDCS protocols may be superior to traditional, single-site tDCS for the enhancement of bimanual motor learning.

Transcranial Direct Current Stimulation for Cognitive Impairment Rehabilitation: A Bibliometric Analysis

As global demographics shift toward an older population, cognitive impairment is becoming increasingly critical. Transcranial Direct Current Stimulation (tDCS), an innovative brain stimulation technique, has the potential to significantly improve cognitive function. Our main aim is to comprehensively analyze the existing literature, identify key aspects of tDCS research in the rehabilitation of cognitive impairment, and predict future trends in this field. We used the Web of Science (WOS) database to search for English articles and reviews relevant to this topic. For visual analysis of the literature, we employed the WOS analysis tool, CiteSpace, along with VOSviewer software to ensure comprehensive analysis. We included 2940 articles published between 1998 and 2023. Over 25 years, annual publications and citations in this field increased steadily, peaking at 379 articles in 2021. Michael A. Nitsche was a major contributor. Most articles came from developed countries, primarily North America and Europe, and journals generally had modest impact factors. Research in this field primarily aims to treat cognitive impairment resulting from pathological aging or neuropsychiatric disorders, with a particular focus on specific brain regions. Recently, researchers have integrated various treatment modalities with tDCS techniques to actively investigate effective strategies to mitigate cognitive impairments associated with pathological aging. This study presents the first bibliometric analysis of the literature on tDCS in the rehabilitation of cognitive impairment, highlighting key areas of research and emerging trends. These findings provide critical insights for future tDCS interventions targeting cognitive impairment associated with pathological aging.

Single High-Frequency Repetitive Transcranial Magnetic Stimulation and Intermittent Theta Pulse Stimulation Promote Working Memory Behavior in Participants: An Event-Related Potential Study

ObjectiveRepetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex (L-DLPFC) has an improving effect in cognitive function, but it is still not clear in what specific cognitive domains. We here combined a single session of TMS (HF-rTMS/iTBS) with electroencephalography (EEG) to clarify the effects of magnetic stimulation techniques on executive function, working memory, and visuospatial attention in healthy participants, and to investigate the underlying neurophysiological mechanisms. MethodsFifty-one healthy participants were randomly assigned to three stimulation groups (HF-rTMS, iTBS, and sham groups). Classical psychological paradigms (task-switching, 2-back with visual Oddball) and event-related potentials (ERPs) were performed to compare the behavioral indices of each paradigm before and after the two stimulations, as well as the changes in the ERP components. ResultsAnalysis of behavioral indicators showed that reaction times in the 2-back paradigm were faster after HF-rTMS and iTBS than after sham stimulation. However, no statistically significant differences were observed in the behavioral changes in the task-switching and visual Oddball paradigms. ERP analysis showed that N2 amplitude in the frontal and central regions of the participants increased during the 2-back paradigm following HF-rTMS and iTBS; however, no statistically significant differences were observed between the ERP components of the task-switching and visual Oddball paradigms. ConclusionSingle sessions of HF-rTMS and iTBS on the L-DLPFC specifically enhanced working memory performance, with no significant effects on executive function and visuospatial attention. Both true stimulations elicited more negative N2 in the frontal and central channels during the 2-back paradigm, suggesting increased recruitment of cognitive resources from these brain areas. Although iTBS and HF-rTMS improved working memory behavior, iTBS’s shorter stimulation time suggests it may have greater potential for clinical applications in terms of time-benefit costs.

The study protocol of a double-blind randomized controlled trial of EMDR and multifocal transcranial current stimulation (MtCS) as augmentation strategy in patients with fibromyalgia

BackgroundFibromyalgia (FM) is a generalized, widespread chronic pain disorder affecting 2.7% of the general population. In recent years, different studies have observed a strong association between FM and psychological trauma. Therefore, a trauma-focused psychotherapy, such as Eye Movement Desensitization and Reprocessing (EMDR), combined with a non-invasive brain stimulation technique, such as multifocal transcranial current stimulation (MtCS), could be an innovative adjunctive treatment option. This double-blind randomized controlled trial (RCT) analyzes if EMDR therapy is effective in the reduction of pain symptoms in FM patients, and if its potential is boosted with the addition of MtCS.MethodsNinety-six patients with FM and a history of traumatic events will be randomly allocated to the treatment as usual (TAU) condition, EMDR + active-MtCS condition, or EMDR + sham-MtCS condition. Therapists and patients will be kept blind to MtCS conditions, and raters will be kept blind to both EMDR and MtCS. All patients will be evaluated at baseline, post-treatment, and follow-up at 6 months after post-treatment. Evaluations will assess the following variables: sociodemographic data, pain, psychological trauma, sleep disturbance, anxiety and affective symptoms, wellbeing, self-care, emotional regulation, self-esteem, and cognitive functioning.DiscussionThis study will provide evidence of whether EMDR therapy is effective in reducing pain symptoms in FM patients, and whether the effect of EMDR can be enhanced by MtCS.Trial registration numberThis trial was registered at ClinicalTrials.gov on 2 August 2019, identifier: NCT04084795.

Data-driven assessment of well stimulation in unconventional gas reservoirs

Unconventional gas reservoirs, characterized by their complex geologies and challenging extraction conditions, demand innovative approaches to enhance gas production and ensure economic viability. Well stimulation techniques, such as hydraulic fracturing and acidizing, have become indispensable tools in unlocking the potential of these tight formations. However, the effectiveness of these techniques can vary widely depending on the specific characteristics of the reservoir. In this context, a data-driven approach to assess well stimulation practices offers a promising avenue to optimize recovery processes and reduce uncertainties. This paper presents a comprehensive study that leverages the power of big data analytics and machine learning to analyze and improve well stimulation strategies in unconventional gas reservoirs. By systematically gathering and processing vast arrays of geological, operational, and production data, this study aims to identify patterns and correlations that can predict stimulation outcomes more accurately. The ultimate goal is to develop a robust framework that allows for tailored stimulation designs based on the unique properties of each reservoir, thereby maximizing efficiency and minimizing environmental impacts. This study introduces a new procedure for assessing well stimulation performance, which involves analyzing the EUR through Duong’s model, calculating the key performance indicator of the treatment, and establishing a data-driven model to predict the treatment KPI.

Therapeutic role of Differential Target Multiplexed (DTM) spinal cord stimulation in painful diabetic neuropathy. Case report.

Diabetic peripheral polyneuropathy (DPN) is the most common cause for diabetic foot complications, including diabetic ulcers, Charcot arthropathy, and lower limb amputations. Spinal Cord Stimulation (SCS) is a safe and effective treatment used for pain reduction in neuropathic/nociceptive pain conditions; the most common stimulation modalities used for the management of painful diabetic neuropathy were conventional paresthesia-based and high-frequency SCS, which stimulate the A beta fibers in the dorsal column of the spinal cord. Differential Target Multiplexed (DTM) SCS is a novel paresthesia-free stimulation technique targeting the supportive glial cells in the nervous system, modulating glial cells and neurons with a rebalance of their interactions. We report a case of severe painful DPN who had immediate pain relief after DTM-SCS implantation, with constant pain relief during the 12 months follow-up. We also investigated the effect of neurostimulation on diabetes control, evaluating the preoperative and postoperative glucose metrics using Continuous Glucose Monitoring (CGM) and compared neurophysiological examination results of the peripheral lower limbs' nerves.

Efficacy of Transcranial Direct Current Stimulation (tDCS) on Neuropsychiatric Symptoms in Multiple Sclerosis (MS)-A Review and Insight into Possible Mechanisms of Action.

Introduction: Neuropsychiatric symptoms such as depression and anxiety are a significant burden on patients with multiple sclerosis (MS). Their pathophysiology is complex and yet to be fully understood. There is an urgent need for non-invasive treatments that directly target the brain and help patients with MS. One such possible treatment is transcranial direct current stimulation (tDCS), a popular and effective non-invasive brain stimulation technique. Methods: This mechanistic review explores the efficacy of tDCS in treating depression and anxiety in MS while focusing on the underlying mechanisms of action. Understanding these mechanisms is crucial, as neuropsychiatric symptoms in MS arise from complex neuroinflammatory and neurodegenerative processes. This review offers insights that may direct more focused and efficient therapeutic approaches by investigating the ways in which tDCS affects inflammation, brain plasticity, and neural connections. Searches were conducted using the PubMed/Medline, ResearchGate, Cochrane, and Google Scholar databases. Results: The literature search yielded 11 studies to be included in this review, with a total of 175 patients participating in the included studies. In most studies, tDCS did not significantly reduce depression or anxiety scores as the studied patients did not have elevated scores indicating depression and anxiety. In the few studies where the patients had scores indicating mild/moderate dysfunction, tDCS was more effective. The risk of bias in the included studies was assessed as moderate. Despite the null or near-null results, tDCS may still prove to be an effective treatment option for depression and anxiety in MS, because tDCS produces a neurobiological effect on the brain and nervous system. To facilitate further work, several possible mechanisms of action of tDCS have been reported, such as the modulation of the frontal-midline theta, reductions in neuroinflammation, the modulation of the HPA axis, and cerebral blood flow regulation. Conclusions: Although tDCS did not overall demonstrate positive effects in reducing depression and anxiety in the studied MS patients, the role of tDCS in this area should not be underestimated. Evidence from other studies indicates the effectiveness of tDCS in reducing depression and anxiety, but the studies included in this review did not include patients with sufficient depression or anxiety. Future studies are needed to confirm the effectiveness of tDCS in neuropsychiatric dysfunctions in MS.

Quality Enhancement Techniques for Cow Meat: Current Approaches and Future Directions.

The quality grade of cow meat is often lower than that of steer meat, resulting in economic losses and reduced consumer satisfaction. This review explores various strategies for improving the quality of cow meat, with a focus on slaughter and post-slaughter practices. Certain slaughter methods, including electrical stimulation and suspension techniques, have been shown to improve meat tenderness by alleviating rigor mortis and inducing an increase in sarcomere length. Electrical stimulation triggers an increase in calcium release, which activates proteolytic enzymes, including calpain, resulting in the breakdown of muscle fibers. In contrast, suspension methods, including pelvic suspension, utilize gravity to maintain muscle elasticity. Post-slaughter treatments, which include wet and dry aging, have varying effects on the tenderness and flavor of meat. Wet aging helps retain moisture and activate the meat-tenderizing enzymes, whereas dry aging enhances flavor through moisture evaporation and microbial activity. Several patented technologies, which include electrical stimulation combined with suspension methods, heat treatments, and microbial pre-treatment, have been developed to further improve the tenderness and flavor of meat during slaughter and aging. The application of these techniques promise significant enhancement in the quality and consumer appeal of cow meat.

Contribution and evolution of respiratory muscles function in weaning outcome of ventilator-dependent patients

BackgroundThe present study was designed to investigate the evolution and the impact of respiratory muscles function and limb muscles strength on weaning success in prolonged weaning of tracheotomized patients. The primary objective was to determine whether the change in respiratory muscles function and limb muscles strength over the time is or is not associated with weaning success.MethodsTracheotomized patients who were ventilator dependent upon admission at a weaning center were eligible. Diaphragm function was assessed with the phrenic nerve stimulation technique and with ultrasound to measure the diaphragm thickening fraction (TFdi) and diaphragm excursion (EXdi). Global respiratory muscle function was assessed with the maximal inspiratory pressure (MIP) and the forced vital capacity (FVC). Limb muscle strength was measured with the Medical Research Council Score (MRC). Measurements were made on a weekly basis. Patients were compared according to their outcome at discharge: complete weaning, partial weaning or death.ResultsAmong the 60 patients who were enrolled, 30 patients finally achieved complete weaning, 20 had partial weaning and 10 died. At 6 months, 6 patients were lost of follow-up, 33 achieved complete weaning, 10 had partial weaning and 11 died. In median, 2 (1–9) assessments were performed per patient. Diaphragm dysfunction was present in all patients with a median Ptr,stim of 5.5 cmH2O (3.0–7.5). Ptr,stim, MIP, TFdi and EXdi at admission were not different between patients who achieved complete weaning and their counterparts. At discharge of the weaning center, MIP, Ptr,stim and EXdi significantly increased in patients who achieved complete weaning. The MRC score significantly increased only in patients with complete weaning. At discharge, diaphragm dysfunction was highly prevalent even in patients with complete weaning (Ptr,stim < 11 cmH2O in n = 11 (37%)).ConclusionRespiratory muscle function and limb muscles strength are severely impaired in patients with prolonged weaning from mechanical ventilation. Significant improvement of diaphragm ultrasound indices was associated with successful weaning from mechanical ventilation and ICU-acquired weakness upon admission was significantly associated with good outcome suggesting that it was an amendable determinant of weaning failure in this population.

A critical role of action-related functional networks in Gilles de la Tourette syndrome

Gilles de la Tourette Syndrome (GTS) is a chronic tic disorder, characterized by unwanted motor actions and vocalizations. While brain stimulation techniques show promise in reducing tic severity, optimal target networks are not well-defined. Here, we leverage datasets from two independent deep brain stimulation (DBS) cohorts and a cohort of tic-inducing lesions to infer critical networks for treatment and occurrence of tics by mapping stimulation sites and lesions to a functional connectome derived from 1,000 healthy participants. We find that greater tic reduction is linked to higher connectivity of DBS sites (N = 37) with action-related functional resting-state networks, i.e., the cingulo-opercular (r = 0.62; p < 0.001) and somato-cognitive action networks (r = 0.47; p = 0.002). Regions of the cingulo-opercular network best match the optimal connectivity profiles of thalamic DBS. We replicate the significance of targeting cingulo-opercular and somato-cognitive action network connectivity in an independent DBS cohort (N = 10). Finally, we demonstrate that tic-inducing brain lesions (N = 22) exhibit similar connectivity to these networks. Collectively, these results suggest a critical role for these action-related networks in the pathophysiology and treatment of GTS.

Exploring the Effects of Prefrontal Transcranial Direct Current Stimulation on Brain Metabolites: A Concurrent tDCS-MRS Study.

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique used to modulates cortical brain activity. However, its effects on brain metabolites within the dorsolateral prefrontal cortex (DLPFC), a crucial area targeted for brain stimulation in mental disorders, remain unclear. This study aimed to investigate whether prefrontal tDCS over the left and right DLPFC modulates levels of key metabolites, including gamma-aminobutyric acid (GABA), glutamate (Glu), glutamine/glutamate (Glx), N-acetylaspartate (NAA), near to the target region and to explore potential sex-specific effects on these metabolite concentrations. A total of 41 healthy individuals (19 female, M_age = 25 years, SD = 3.15) underwent either bifrontal active (2 mA for 20 min) or sham tDCS targeting the left (anode: F3) and right (cathode: F4) DLPFC within a 3 Tesla MRI scanner. Magnetic resonance spectroscopy (MRS) was used to monitor neurometabolic changes before, during, and after 40 min of tDCS, with measurements of two 10-min intervals during stimulation. A single voxel beneath F3 was used for metabolic quantification. Results showed a statistically significant increase in Glx levels under active tDCS compared to the sham condition, particularly during the second 10-min window and persisting into the post-stimulation phase. No significant changes were observed in other metabolites, but consistent sex differences were detected. Specifically, females showed lower levels of NAA and GABA under active tDCS compared to the sham condition, while no significant changes were observed in males. E-field modeling showed no significant differences in field magnitudes between sexes, and the magnitude of the e-fields did not correlate with changes in Glx levels between active and sham stimulation during the second interval or post-stimulation. This study demonstrates that a single session of prefrontal tDCS significantly elevates Glx levels in the left DLPFC, with effects persisting post-stimulation. However, the observed sex differences in the neurochemical response to tDCS were not linked to specific stimulation intervals or variations in e-field magnitudes, highlighting the complexity of tDCS effects and the need for personalized neuromodulation strategies.