Frontiers in Neuroscience最新文献

This review delves into the emerging field of cerebellar Transcranial Magnetic Stimulation (TMS) in the rehabilitation of limb dysfunction following a stroke. It synthesizes findings from randomized controlled trials and case studies, examining the efficacy, safety, and underlying mechanisms of cerebellar TMS. The review outlines advancements in TMS technologies, such as low-frequency repetitive TMS, intermittent Theta Burst Stimulation, and Cerebello-Motor Paired Associative Stimulation, and their integration with physiotherapy. The role of the cerebellum in motor control, the theoretical underpinnings of cerebellar stimulation on motor cortex excitability, and the indirect effects on cognition and motor learning are explored. Additionally, the review discusses current challenges, including coil types, safety, and optimal timing and modes of stimulation, and suggests future research directions. This comprehensive analysis highlights cerebellar TMS as a promising, though complex, approach in stroke rehabilitation, offering insights for its clinical optimization.

Introduction: Ketamine demonstrates robust and rapidly occurring antidepressant effects in patients with difficult-to-treat major depressive disorder. Ketamine's antidepressant effects and its impact on functional networks in non-resistant forms of major depressive disorder are expected to provide valuable insight into ketamine's mechanism of action related to depression.

Methods: This study employs an existing network model of major depressive disorder to investigate the effects of ketamine on resting state connectivity in a therapy-non-resistant major depressive disorder population. In a randomized, double-blind, placebo-controlled, cross-over study, 0.5 mg/kg racemic ketamine or 0.9%NaCl was administered intravenously in 16 MDD patients. We applied resting-state functional magnetic resonance imaging (rs-fMRI) to explore changes in functional brain connectivity directly at 50, 80 and 165 min (acute) and 24 h (delayed) following ketamine administration. A clinician-rated 10-item scale (MADRS) was administered at 165 min and 24 h after ketamine administration. Connections-of-interest (COIs) were based on the previously published corticolimbic-insular-striatalpallidal-thalamic (CLIPST) circuitry model of major depressive disorder.

Results: Compared with placebo, ketamine significantly (p < 0.0014) reduced the mean (SD) MADRS total score from 21.2 (5.9) pre-dose to 10.3 (4.6) 24 h post-dose. At both acute (p < 0.0172) and delayed (p < 0.0488) time points, significant rs-fMRI connectivity changes occurred only in MDD-related COIs as proposed by the CLIPST model. No changes in functional connectivity were found in non-CLIPST connections.

Discussion: This study demonstrates that ketamine specifically affects depression-related circuitry. Analyzing functional connectivity based on a neurocircuitry model of a specific CNS disease and drug action may be an effective approach that could result in a more targeted analysis in future pharmaco-fMRI studies in CNS drug development.

Objective: Adolescents with major depressive disorder (MDD) exhibit abnormal dynamic functional connectivity (dFC) patterns, but it remains unclear whether these aberrant dFC patterns are linked to antidepressant treatment. The aim of this study is to investigate whether dFC patterns will be changed by antidepressant treatment, as well as whether baseline dFC pattern could predict treatment response in adolescent MDD patients.

Method: We included 35 drug-naïve, first-episode MDD adolescents (age 14.40 ± 1.24; 8 males and 27 females) and 24 healthy controls (HCs, age 14.21 ± 1.41; 11 males and 13 females). All MDD adolescents received 6 weeks of antidepressant treatment. Resting state and T1 MRI data were collected in MDD adolescents before and after treatment and in HCs. Independent component analysis (ICA) was used to compare the different dFC pattern between MDD adolescents and HCs at baseline, as well as which between before and after treatment in MDD adolescents. Finally, Pearson correlation and multivariate linear regression analyses were used to explore the associations between dFC pattern and changed score of BDI in MDD adolescents.

Results: The mean dFC value between right inferior frontal gyrus (IFG) and bilateral insular cortex (IC; right, r = -0.461, p-FDR = 0.012; left, r = -0.518, p-FDR = 0.007) at baseline were negatively correlated with BDI score reduction. The mean dFC value between left frontal pole (FP) and right superior parietal lobule (SPL) after treatment was positively correlated with BDI score reduction (r = 0.442, p-FDR = 0.014). And the mean dFC values between right IFG and bilateral IC (right, β = -1.563, p-FDR = 0.021; left, β = -1.868, p-FDR = 0.012) at baseline could predict antidepressant treatment response.

Conclusion: These findings demonstrate that dFC patterns between some brain areas could be a prospective factor for predicting antidepressant treatment response.

Introduction: Music has a profound impact on human emotions, capable of eliciting a wide range of emotional responses, a phenomenon that has been effectively harnessed in the field of music therapy. Given the close relationship between music and language, researchers have begun to explore how music influences brain activity and cognitive processes by integrating artificial intelligence with advancements in neuroscience.

Methods: In this study, a total of 120 subjects were recruited, all of whom were students aged between 19 and 26 years. Each subject is required to listen to six 1-minute music segments expressing different emotions and speak at the 40-second mark. In terms of constructing the classification model, this study compares the classification performance of deep neural networks with other machine learning algorithms.

Results: The differences in EEG signals between different emotions during speech are more pronounced compared to those in a quiet state. In the classification of EEG signals for speaking and quiet states, using deep neural network algorithms can achieve accuracies of 95.84% and 96.55%, respectively.

Discussion: Under the stimulation of music with different emotions, there are certain differences in EEG between speaking and resting states. In the construction of EEG classification models, the classification performance of deep neural network algorithms is superior to other machine learning algorithms.

Objective: Electrical stimulation of the pudendal nerve, pelvic nerve, sacral dorsal root ganglion (DRG), and spinal cord has been explored to treat urinary incontinence and overactive bladder (OAB). This study introduces sacral intraspinal microstimulation (ISMS) as a novel method to inhibit spontaneous bladder reflexes in anesthetized cats. In addition, we investigated the effects of intermittent and switching stimulation patterns on bladder inhibition.

Methods: The electrode was implanted in the dorsal horn of the S2 spinal cord. Bladder pressure was recorded under isovolumetric conditions, and the stimulation parameters were adjusted to inhibit spontaneous bladder contractions. Nonlinear dynamic methods, including chaos theory, were employed to analyze the complexity of bladder reflexes.

Results: Results demonstrated that ISMS targeting the dorsal horn of the S2 spinal segment effectively suppressed high-amplitude spontaneous contractions. Furthermore, bladder reflexes exhibited complex dynamics, ranging from regular to chaotic patterns, with transitions between these states. Importantly, ISMS was able to stabilize these chaotic dynamics, leading to more controlled bladder behavior.

Conclusion: These findings suggest that sacral ISMS offers a promising, targeted alternative to traditional stimulation therapies, potentially providing a new therapeutic approach for managing OAB and urinary incontinence by regulating chaotic bladder activity.

Recently, electromyographic (EMG) signals of auricular muscles have been shown to be an indicator of spatial auditory attention in humans, based on a vestigial pinna-orienting system. Because spatial auditory attention in a competing speaker task is closely related to the more generalized concept of attentional effort in listening, the current study investigated the possibility that the EMG activity of auricular muscles could also reflect correlates of effortful listening in general. Twenty participants were recruited. EMG signals from the left and right superior and posterior auricular muscles (SAM, PAM) were recorded while participants attended a target podcast in a competing speaker paradigm. Three different conditions, each more difficult and requiring a higher amount of effortful listening, were generated by varying the number and pitch of distractor streams, as well as the signal-to-noise ratio. All audio streams were either presented from a loudspeaker placed in front of the participants (0°), or in the back (180°). Overall, averaged PAM activity was not affected by different levels of effortful listening, but was significantly larger when stimuli were presented from the back, as opposed to the front. Averaged SAM activity, however, was significantly larger in the most difficult condition, which required the largest amount of effort, compared to the easier conditions, but was not affected by stimulus direction. We interpret the increased SAM activity to be the response of the vestigial pinna-orienting system to an effortful stream segregation task.

Objective: Although fMRI has been widely used in the field of acupuncture. However, the literature analysis in this field still has significant differences. This study summarizes the current status of functional magnetic resonance imaging (fMRI) in the field of acupuncture and moxibustion and predicts its future trends through Web of Science bibliometric analysis.

Methods: This study uses "fMRI" and "acupuncture" as keywords to search for literature related to functional magnetic resonance imaging (fMRI) in acupuncture research in the Web of Science Core Collection database from January 1, 2004, to April 30, 2024. Visualization analyses were conducted using Citespace (version 6.3 R1) and VOSviewer (version 1.6.20). Citespace was employed to analyze annual publications, countries, institutions, keywords, and co-cited references. VOSviewer was used to analyze authors and co-cited authors, as well as journals and co-cited journals.

Results: From 2004 to 2024, a total of 967 publications were retrieved, of which 557 were included after screening. Despite annual fluctuations, the overall trend shows an increase. China and the Chinese Academy of Sciences are the countries and institutions with the highest number of publications, with Tian, J being the author with the most publications, and Kong, J having the highest Co-citation frequency. The article by Dhond, RP, published in 2008, has the highest Co-citation frequency among the co-cited literature. Evidence-based Complementary and Alternative Medicine is the journal with the most publications, while Neuroimage is the co-cited journal with the highest citation frequency. Keyword co-occurrence and burst reveal the main research hotspots, including the diversity of intervention methods, cortical activation, mechanisms related to pain-associated diseases, and brain-related diseases. Keyword burst detection reflects emerging trends, including meta-analysis and systematic reviews, the relationship between ischemic stroke and women, and the connection between mild cognitive impairment and prevention.

Conclusion: This study employs bibliometric methods to explore the current status, research hotspots, and frontier issues regarding the application of functional magnetic resonance imaging (fMRI) technology in the field of acupuncture, providing new perspectives and directions for acupuncture fMRI research.

Classical conditioning is a fundamental associative learning process in which repeated pairings of a conditioned stimulus (CS) with an unconditioned stimulus (US) lead to the CS eliciting a conditioned response (CR). Previous research has identified key neural regions involved in processing reward-predicting cues and mediating licking behavior. However, the mechanisms that sustain high conditioned response rates across repeated sessions remain elusive, particularly regarding how the reward expectation is represented on a session-by-session basis. While early learning phases in classical conditioning have been extensively studied, the neural mechanisms that support consistent performance over time remain unclear. In this study, we sought to understand how cortical regions, particularly the posterior parietal cortex (PPC), contribute to maintaining high CR rates across sessions. Using the core complex framework derived from Integrated Information Theory (IIT), we explored the dynamics of neural networks during sessions of high CR performance. Our findings suggest that while traditional functional connectivity (FC) methods struggled to capture the complexity of sustained behavioral engagement, the core complex framework revealed key regions, notably the PPC, that were significantly correlated with enhanced CR sessions. This work suggests the potential role of the PPC in supporting reward expectations and maintaining consistent behavioral responses. By applying the core complex framework to investigate neural substrates of sustained behavior, we provide novel insights into the interaction of cortical networks during classical conditioning, offering promising directions for future research in associative learning and behavior.

Stress-protective effects have been reported for M. vaccae NCTC 11659 and M. vaccae ATCC 15483^T. However, it remains to be investigated whether also closely related rapidly growing environmental saprophytic non-tuberculous mycobacteria (NTM) species have protective effects against the negative consequences of chronic psychosocial stress. Therefore, the aim of the current study was to assess whether repeated i.g. administrations of a heat-inactivated preparation of Mycobacterium aurum DSM 33539 prior to 19 days of chronic subordinate colony housing (CSC) are able to ameliorate the negative effects of this preclinically validated mouse model for chronic psychosocial stress on subsequent dextran sulfate sodium (DSS) colitis in male C57BL/6N mice. The results of the present study show that repeated i.g. administrations of M. aurum DSM 33539 have stabilizing effects on the composition of the gut microbiome, indicated by the findings that M. aurum DSM 33539 prevented CSC-induced increases in the relative abundances of the colitogenic phyla Desulfobacterota and Deferribacterota. Indeed, the relative abundance of Deferribacterota on day 19 was strongly correlated with histological damage to the colon. In line with the latter, M. aurum DSM 33539 was further protective against the aggravating effects of stress on subsequent DSS colitis. Collectively, our findings confirm and extend previous findings from our group and suggest that the stress-protective effects reported for M. vaccae NCTC 11659 and M. vaccae ATCC 15483^T are generalizable also to other NTM species.