Frontiers in Neuroscience最新文献

Aim: This study aimed to investigate the brain activity involved in visually evoked auditory response (vEAR) using high-density electroencephalography (EEG) and explore the differences in connections between visual and auditory cortex.

Methods: Thirty-seven subjects with vEAR and Thirty four subjects without vEAR, matched by age and gender, were recruited. The hearing threshold, years of education, and the Trail Making Test (versions A and B) results were collected from all patients. All participants underwent a 256-channel EEG, and neurophysiological differences were evaluated using standardized low-resolution brain electromagnetic tomography (sLORETA).

Results: Trail Making Test scores in vEAR group were 17.3 ± 2.70 s and 26.28 ± 3.83 s for versions A and B, respectively, and 20.13 ± 6.88 s and 46.65 ± 5.971 s, respectively, in non-vEAR group. Significant difference in version B score was observed between two groups. Compared with non-vEAR group, significant differences were observed at the delta (p = 0.005), theta (p = 0.016), alpha1 (p = 0.016), alpha2 (p = 0.011), beta3 (p = 0.024), and gamma (p = 0.048) frequency bands in vEAR group. In addition, vEAR group showed significantly reduced activation of the posterior cingulate cortex (BA31, p = 0.0306) at the alpha2 frequency band and the insular cortex (BA13, p = 0.0306) at the beta2 frequency band. Moreover, significantly increased synchronized beta3 connectivity was found between the right part of the cingulate cortex (BA30) and the right primary auditory cortex (BA41) in vEAR group (p = 0.045).

Conclusion: vEAR group showed stronger regional connection characteristics than non-vEAR group, which may represent a neural signature associated with vEAR.

Background/objectives: The existing literature on normative data for accommodative facility (AF) in African populations is limited to high school students. There is no normative data for vergence facility (VF) in African children, so there are no benchmarks for comparison in case analysis, diagnosis, and management. The study aimed to establish normative data for AF in children aged 8-12 years. Additionally, the study sought to determine normative data for VF in children aged 8-17 years in the Cape Coast metropolis, Ghana.

Methods: Normal children (510) were recruited through a comprehensive oculo-visual examination of 2,300 basic school-going children, aged 8-17 years. AF was measured with a ± 2D flipper lens for 1 min. VF was measured with a 3-base-in/12 base-out flipper prism for 1 min. Normative data were derived using the median with interquartile ranges (IQR) and considering the spread of data within the minimum and maximum ranges.

Results: A median value of 13 cpm with IQR of 4 cpm was determined for monocular accommodative facility (MAF). The normative central tendency for MAF for school children 8-17 years ranges from 9 to 17 cpm; data were widely spread, with a minimum of 4 and a maximum of 20 cpm. A median value of 13 cpm with IQR of 3 cpm was determined for the binocular accommodative facility (BAF). The normative central tendency for BAF for school children aged 8-17 years ranged from 9 to 14 cpm; data were widely spread, with a minimum of 5 and a maximum of 20 cpm. A median value of 14 cpm with IQR of 4 cpm was determined for VF. The normative central tendency for VF for school children 8-17 years ranged from 10 to 18 cpm; data were widely spread, with a minimum of 6 and a maximum of 21 cpm.

Conclusion: The normative data apply only to similarly aged Ghanaian children and serve as standards for comparison to clinical data for MAF, BAF, and VF during case analysis.

This paper presents a neuromorphic, event-driven tactile sensing system for soft, large-area skin, based on the Dynamic Vision Sensors (DVS) integrated with a flexible silicone optical waveguide skin. Instead of repetitively scanning embedded photoreceivers, this design uses a stereo vision setup comprising two DVS cameras looking sideways through the skin. Such a design produces events as changes in brightness are detected, and estimates press positions on the 2D skin surface through triangulation, utilizing Density-Based Spatial Clustering of Applications with Noise (DBSCAN) to find the center of mass of contact events resulting from pressing actions. The system is evaluated over a 4,620 mm probed area of the skin using a meander raster scan. Across 95 % of the presses visible to both cameras, the press localization achieved a Root-Mean-Squared Error (RMSE) of 4.66 mm. The results highlight the potential of this approach for wide-area flexible and responsive tactile sensors in soft robotics and interactive environments. Moreover, we examined how the system performs when the amount of event data is strongly reduced. Using stochastic down-sampling, the event stream was reduced to 1/1,024 of its original size. Under this extreme reduction, the average localization error increased only slightly (from 4.66 mm to 9.33 mm), and the system still produced valid press localizations for 85 % of the trials. This reduction in pass rate is expected, as some presses no longer produce enough events to form a reliable cluster for triangulation. These results show that the sensing approach remains functional even with very sparse event data, which is promising for reducing power consumption and computational load in future implementations. The system exhibits a detection latency distribution with a characteristic width of 31 ms.

Introduction: Functional near-infrared spectroscopy (fNIRS) has emerged as a promising neuroimaging modality for investigating cortical activity in auditory and vestibular domains. Its portability, device compatibility, and motion tolerance make it particularly suited for use in populations that are challenging to study with conventional neuroimaging techniques, such as infants and cochlear implant (CI) users. The present study aims to explore the potential and limitations of this neuroimaging technique in the audiological and vestibular fields, offering an integrated perspective across pediatric, adult and elderly populations.

Methods: A narrative review of studies using fNIRS in hearing loss, tinnitus, and vestibular disorders was conducted through searches in PubMed and Scopus up to March 2025. Studies were included if they employed fNIRS to investigate cortical responses in individuals with diagnosed hearing loss, chronic tinnitus or to investigate vestibular function.

Results: A total of 60 studies were reviewed: 36 on hearing loss, 11 on tinnitus, and 13 on vestibular disorders. In hearing research, fNIRS successfully identified cortical activation patterns related to auditory perception, speech processing, and cross-modal plasticity in CI users across development, adulthood and aging. The technique showed prognostic potential in predicting CI outcomes and monitoring listening effort and cognitive load. In tinnitus research, fNIRS consistently demonstrate hyper-activation in the auditory cortex and altered functional connectivity with frontal-limbic networks, reflecting sensory, cognitive, and emotional involvement. The technique was sensitive to treatment effects following interventions such as transcranial stimulation, acupuncture, and cochlear implantation. In vestibular research, fNIRS enabled the mapping of cortical networks involved in balance control and multisensory integration during various stimulation paradigms, including caloric testing, motion platforms, and optic flow in virtual environments. Although current applications are mostly exploratory, findings suggest fNIRS can capture vestibular-related cortical activity in real-world conditions.

Conclusion: fNIRS offers a valuable, non-invasive, and ecologically valid method for investigating auditory and vestibular function across the lifespan. In hearing and tinnitus research, it shows strong potential for clinical translation, especially if methodological standardization is achieved. Applications in vestibular research remain preliminary but promising.

Introduction: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder causing progressive motor neuron death in cortex, brainstem and spinal cord. The most common genetic cause is the G4C2 hexanucleotide repeat expansion in the non-coding region of exon 1 of C9ORF72, accounting for ~40% of familial and ~7% of sporadic ALS. RNA dysregulation is increasingly recognized as a key contributor to ALS pathogenesis. This study aimed to identify specific microRNAs (miRNAs) involved in motor neuron degeneration in C9ORF72-ALS.

Methods: We profiled 754 miRNAs in human post-mortem spinal cord tissue from C9ORF72-ALS patients and healthy donors. Laser capture microdissection isolated ventral horn regions, and in silico target prediction identified potential genes and pathways regulated by differentially expressed miRNAs. Target genes were validated by Real time PCR.

Results: Two subsets of miRNAs were exclusively expressed in ventral horn regions: miR-200b-3p and miR-346 in C9ORF72-ALS patients, and miR-30d-5p, miR-106b-5p and miR-135a-5p in healthy donors. Target prediction and molecular analysis identified putative genes and pathways linked to cell death, inflammation, protein metabolism, DNA modification, excitotoxicity, autophagy and vesicles trafficking.

Discussion: This study identifies specific miRNAs and their target genes as key molecules in motor neuron degeneration in C9ORF72-ALS. Restoring their expression could represent a therapeutic approach for ALS.

Background: Current clinical research suggests that the ketogenic diet (KD) intervention can alleviate Parkinson's disease (PD) symptoms. However, the underlying mechanisms remain unclear. This pilot study explored the potential link between KD-induced clinical improvements and gut microbiota alterations.

Methods: We engaged 27 PD patients in a 12-week ketogenic dietary trial (16 completed) and employed 16S rRNA sequencing to analyze gut microbiota differences compared to 27 healthy controls.

Results: Baseline analysis revealed distinct dysbiosis in PD patients, characterized by increased abundance of Enterobacteriaceae. Following the 12-week intervention, patients exhibited significant improvements in both motor (MDS-UPDRS Part III, p < 0.001) and non-motor symptoms (NMSS, p < 0.0001). These clinical improvements were accompanied by specific microbial shifts: a significant increase in Enterococcus and Synergistota, and a decrease in Alloprevotella.

Conclusion: These findings suggest that the therapeutic effects of the ketogenic diet in PD are associated with specific remodeling of the gut microbiota, particularly the enrichment of potential beneficial taxa and reduction of pro-inflammatory genera.

Clinical trial registration: https://www.chictr.org.cn/index.html, Unique Identifier: ChiCTR2100045394.

Introduction: Perception operates as rhythmically structured sampling in which temporal predictions determine when incoming signals are weighted. Fixational eye movements carry opposing consequences, enhancing acuity yet inducing brief peri-saccadic suppression, suggesting that their timing is paced by expected, salient rhythms. Auditory scenes can be parsed into competing streams that unfold over time. If fixation dynamics are shaped by temporal expectation, and auditory streaming imposes a percept-dependent temporal structure on otherwise identical acoustics, then fixational eye movements might provide a window into how listeners parse sound over time. We asked whether fixational eye movements reflect the perceived rather than the physical temporal organization of an ambiguous ABA- pattern.

Methods: While listeners fixated and either attended High, Low, or All tones (Experiment 1, n = 15) or freely reported their percept (Experiment 2, n = 15), we recorded binocular eye position (500 Hz) and quantified microsaccade (MS) dynamics and eye-velocity spectra.

Results: Across both experiments, eye-velocity spectra showed a percept-dependent redistribution between 2 and 4 Hz, with relative power shifting with the instructed/reported stream. A normalized 4-2 Hz index (ΔPSD) separated Low-tone from High-tone percepts across procedures. Time-resolved analyses further revealed within-trial waxing-and-waning of 2 vs. 4 Hz dominance, consistent with bistable fluctuations in maintaining a stream. Moreover, microsaccade reaction time (msRT), aligned to the onset of the sound sequence, differed significantly depending on the percept.

Discussion: These findings extend oculomotor inhibition beyond discrete events, positioning fixation dynamics as a sensitive, report-free marker of auditory scene organization. We discuss mechanistic links to temporal attention and active sensing, and implications for a multisensory timing framework.

Bainbridge-Ropers syndrome (BRPS, OMIM #615485) is a rare, heterogeneous autosomal dominant genetic disease that is mainly characterized by intellectual disability (ID) of varying degrees, developmental delay (DD), language impairments, failure to thrive, behavioral issues, hypotonia, feeding difficulties, and distinctive craniofacial features. It is caused by heterozygous pathogenic variants in the additional sex combs-like 3 (ASXL3, OMIM #615115) gene. In this study, four Chinese patients were diagnosed with BRPS caused by ASXL3 variants through whole exome sequencing. We detected two novel and two previously reported variants of the ASXL3 gene (NM_030632.3) in these 4 unrelated Chinese patients: two novel variants, namely, c.1276del (p.Val426^*) and c.3750del (p.Glu1251Asnfs^*5), and two recurrent variants, namely, c.4330C>T (p.Arg1444^*) and c.4336_4337delAG (p.Arg1446fs^*2). All four patients had a clinical profile similar to that associated with BRPS. Compared with previously reported cases of BRPS, these patients exhibited novel complications, including long eyelashes, congenital laryngeal cartilage hypoplasia and dextrocardia. These findings broaden our understanding of the mutational and clinical spectrum of BRPS, emphasizing the importance of long-term monitoring and vigilance regarding potential complications, such as cardiac abnormalities, in BRPS patients.

Background: Maternal immune activation (MIA) is a risk factor for neurodevelopmental disorders (NDDs) in offspring. While MIA-induced changes in the gut bacterial communities of offspring and their metabolites have been linked to behavioral abnormalities, the effects of MIA on the gut fungal communities and their mycotoxin-associated metabolites in offspring remain poorly characterized.

Methods: In this study, MIA was modeled in pregnant rats through intraperitoneal injection of 5 mg/kg Poly I:C on gestational day 15. The model's efficacy was validated using behavioral assessments, including the open-field test, elevated plus maze, and Morris water maze. Internal transcribed spacer (ITS) sequencing and untargeted metabolomics analysis were employed to detect the alterations of gut fungal microbiota and mycotoxin levels.

Results: Poly I:C-exposed offspring exhibited increased anxiety and cognitive deficits. Meanwhile, Poly I:C induces sex-related differences in gut fungal communities and mycotoxin levels in juvenile offspring rats. Several fungal genera and mycotoxins were significantly correlated with variations in anxiety-like behaviors and spatial learning performance.

Discussion: Our findings suggest that MIA-induced behavioral deficits in offspring are accompanied by sex-specific disruptions in gut fungal composition and mycotoxin metabolism, which highlights the need for further intervention studies to establish causality and elucidate the underlying mechanisms of gut fungi and mycotoxins in NDDs.

Background: Preclinical and clinical studies suggest that the multimodal antidepressant vortioxetine may offer a valuable therapeutic option in the treatment of depression associated with neurological disorders, including Parkinson's disease (PD).

Objectives: To compare the effect of vortioxetine and the SSRI sertraline in the treatment of PD and comorbid depression, placing emphasis on peripheral inflammation markers.

Methods: This is an observational longitudinal study. We have recruited 33 patients affected by PD with comorbid depression, evaluated for motor and non-motor symptoms, depression, and peripheral and soluble markers of inflammation at baseline and at the end of antidepressant treatment. Patients were divided into two groups treated with either vortioxetine (10-20 mg/day) or sertraline (50 mg/day) for 4 months. A group of 12 healthy controls was also used for comparative purposes.

Results: At baseline PD patients showed a higher number of "classical" monocytes and a lower number of "non-classical" monocytes and myeloid dendritic cells (mDCs). The number and activity of DCs generated from isolated monocytes were also lower in PD patients. While both sertraline and vortioxetine treatment further reduced the number of mDCs, only vortioxetine had a restorative effect on CD40- and CD54-expressing DCs and their function. Both drugs display an antidepressant activity, but vortioxetine was superior to sertraline in improving cognitive function, anxiety, anhedonia, and apathy.

Conclusion: These data evaluate for the first time the immunomodulatory effects of two different treatments in PD patients with comorbid depression, highlighting the greater immunomodulatory capacity of vortioxetine.