Frontiers in Human Neuroscience最新文献

Background: Low-intensity transcranial focused ultrasound (tFUS) is a brain stimulation approach that holds promise for the treatment of brain-based disorders. Studies in humans have shown that tFUS can successfully modulate perfusion in focal sonication targets, including the amygdala; however, limited research has explored how tFUS impacts large-scale neural networks.

Objective: The aim of the current study was to address this gap and examine changes in resting-state connectivity between large-scale network nodes using a randomized, double-blind, within-subjects crossover study design.

Methods: Healthy adults (n = 18) completed two tFUS sessions, 14 days apart. Each session included tFUS of either the right amygdala or the left entorhinal cortex (ErC). The inclusion of two active targets allowed for within-subjects comparisons as a function of the locus of sonication. Resting-state functional magnetic resonance imaging was collected before and after each tFUS session.

Results: tFUS altered resting-state functional connectivity (rsFC) within and between rs-network nodes. Pre-to-post sonication of the right amygdala modulated connectivity within nodes of the salience network (SAN) and between nodes of the SAN and the default mode network (DMN) and frontoparietal network (FRP). A decrease in SAN to FPN connectivity was specific to the amygdala target. Pre-to-post sonication of the left ErC modulated connectivity between the dorsal attention network (DAN) and FPN and DMN. An increase in DAN to DMN connectivity was specific to the ErC target.

Conclusion: These preliminary findings may suggest that tFUS induces neuroplastic changes beyond the immediate sonication target. Additional studies are needed to determine the long-term stability of these effects.

Introduction: Non-fluent variant of primary progressive aphasia (nfvPPA) is a neurodegenerative disorder with a predominantly speech and language impairment. Apraxia of speech and expressive agrammatisms along with decreased speech fluency and impaired grammar comprehension are the most typical disorder manifestations but with the course of the disease other language disturbances may also arise. Most studies have investigated these symptoms individually, and there is still no consensus on whether they have similar or different neuroanatomical foundations in nfvPPA. In addition, only few works have focused on the functional connectivity correlates. The aim of our study was to simultaneously investigate functional and structural brain-language associations in one group of nfvPPA.

Methods: Twenty eight patients were enrolled and underwent brain MRI and language assessment. Apraxia of speech, expressive and receptive agrammatisms, repetition, naming and single word comprehension correlates were identified using voxel-based morphometry and resting-state functional MRI (ROI-to-ROI analysis).

Results and discussion: Among the structural correlates, the most common were inferior frontal gyrus (was associated with fluency, both expressive and receptive agrammatisms) and supramarginal gyrus (apraxia of speech, receptive agrammatisms, naming and repetition). Apart from that, neuroanatomical foundations were different for each of the core nfvPPA language domains, including superior parietal lobule involvement in fluency, temporoparietal areas in receptive agrammatisms and supplemental motor area in apraxia of speech. Functional correlations were even more diverse. In general, connectivity decrease between temporoparietal structures was more typical for expressive and receptive agrammatisms, single word comprehension and naming, while apraxia of speech, fluency and repetition showed connectivity disruption mainly among the frontoparietal region and subcortical structures. Overall, extensive structural and functional changes are involved in the development of language and speech disturbances in nfvPPA with distinctive neuroanatomical foundations for each domain.

The brain's response to cognitive demands hinges on sufficient blood flow, with changes in brain hemodynamics serving as a reflection of this process. Certain bioactive compounds found in our diet, such as caffeine, polyphenols, and nitrate, can acutely impact brain hemodynamics through diverse neural, vasoactive, and metabolic mechanisms. Functional Near-Infrared Spectroscopy (fNIRS) offers a non-invasive and real-time method to investigate these effects. Despite their potential, fNIRS studies investigating the acute impacts of bioactive compounds on cognition face methodological gaps, especially in controlling confounding factors. Given the impact of these confounding effects, which can be significant due to the relatively limited sample size of such studies, there is a need to refine the methodologies employed. This review proposes recommendations to enhance current methodologies in the research field, focusing on key aspects of the data collection phase, including research design, experimental paradigms, and participant demographics, and their integration into the analysis phase. Ultimately, it seeks to advance our understanding of the effects of bioactive compounds on cognitive functions to contribute to the development of targeted nutritional interventions for improved brain health.

We review and synthesize recent religion and brain studies and find that at a broad network neuroscience level, religious/spiritual experiences (RSEs) appear to depend crucially upon interactions between the default mode network (DMN), the frontoparietal network (FPN), and the salience network (SN). We see this general result as broadly consistent with Menon's et al. "Triple Network or Tripartite Model" (TPM) of neuropsychiatric function/dysfunction. A TPM cycling model is here offered to account for details of neural bases of an array of RSE phenomena including ecstatic seizures, neuroimaging of religious participants, psychedelically induced mystical states and perceptions of supernatural agents. To adequately account for SA perceptions, however, recent evidence suggests that REM sleep and dreaming mechanisms likely play a role. Future research should examine neurodevelopmental mechanisms of acquired SA perceptions as well as societal-level effects such as brain mediated religious beliefs of in-group cohesion and out-group hostility.

Background: The majority of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) only show mild respiratory symptoms. However, some patients with SARS-CoV-2 display neurological symptoms. Data on the exact prevalence and course of cognitive symptoms are often limited to patient reported outcomes or studies recruited at specialized centers.

Methods: For this prospective, non-interventional population based POPCOV2 study, 156 subjects who performed SARS-CoV-2 testing in the Düsseldorf metropolitan area at public test centers between December 2020 and February 2022 were recruited by handouts. SARS-CoV-2-positive and negatively tested subjects were included within the first seven days after the PCR test results. Cognitive testing was performed at baseline during home quarantine and after 4-6 as well as 12-14 weeks of follow-up. Individuals were examined remotely by videocalls using the Symbol Digit Modalities Test (SDMT) and the Montreal Cognitive Assessment (MoCA) in addition to the Brief Fatigue Inventory (BFI) and the Beck Depression Inventory-Fast Screen (BDI-FS).

Results: At baseline, the SARS-CoV-2-positive group presented with higher levels of fatigue in the BFI. In both the SARS-CoV-2-positive and SARS-CoV-2-negative groups, some subjects presented attention and memory deficits, defined as a z-score < -1,65 on the SDMT or < 26 points on the MoCA (SDMT: 22.9% in the positive and 8.8% in the negative group, p = 0.024; MoCA: 35.6% in the positive and 27.3% in the negative group, p = 0.313). MoCA and SDMT improved over time in both groups. For MoCA scores, a significant difference between the two groups was only seen at the first follow-up. SDMT z-scores did not differ at any time between the groups.

Conclusion: These results support previous evidence that mild SARS-CoV-2 infections are associated with increased fatigue. However, we found relevant rates of cognitive impairment not only in the infected but also in the control group. This underlines the importance of including a control group in such investigations.

Background: The status of vitamin D has been proposed to have an impact on cognition. Gray matter volume (GMV) is a potential marker of cognitive function. We investigated whether lower serum 25-hydroxyvitamin D level was associated with reduced cerebral GMV in Parkinson's disease with non-dementia (PDND) patients.

Methods: Baseline neuropsychiatric performance and serum 25-hydroxyvitamin D levels were examined in 24 PDND patients and 24 healthy controls (HCs). A set of cognitive scales were used to evaluate the cognition. Voxel-based morphometry (VBM) was performed to calculate each PDND patient's GMV, based on structural magnetic resonance imaging data. Associations between serum 25-hydroxyvitamin D levels, cognition, and GMV were evaluated.

Results: The serum 25-hydroxyvitamin D levels of the PDND group were significantly lower than those of the HC group. The simple linear regression analyses between serum 25-hydroxyvitamin D levels and the scores of subtests that analyzed cognitive function showed that serum 25-hydroxyvitamin D levels were negatively correlated with Trail Making Test-A scores and positively correlated with Symbol Digit Modalities Test and Auditory Verbal Learning Test scores. Multiple regression analyses revealed a positive correlation between the right fusiform gyrus GMV and serum 25-hydroxyvitamin D levels.

Conclusion: We hypothesized that the lower serum 25-hydroxyvitamin D level in patients with PDND might affect auditory word learning and spatial cognition ability by reducing the gray matter volume of the right fusiform gyrus, thereby leading to deterioration of semantic understanding and memory function.

The Earth's abundance of iron has played a crucial role in both generating its geomagnetic field and contributing to the development of early life. In ancient oceans, iron ions, particularly around deep-sea hydrothermal vents, might have catalyzed the formation of macromolecules, leading to the emergence of life and the Last Universal Common Ancestor. Iron continued to influence catalysis, metabolism, and molecular evolution, resulting in the creation of magnetosome gene clusters in magnetotactic bacteria, which enabled these unicellular organisms to detect geomagnetic field. Although humans lack a clearly identified organ for geomagnetic sensing, many life forms have adapted to geomagnetic field-even in deep-sea environments-through mechanisms beyond the conventional five senses. Research indicates that zebrafish hindbrains are sensitive to magnetic fields, the semicircular canals of pigeons respond to weak potential changes through electromagnetic induction, and human brainwaves respond to magnetic fields in darkness. This suggests that the trigeminal brainstem nucleus and vestibular nuclei, which integrate multimodal magnetic information, might play a role in geomagnetic processing. From iron-based metabolic systems to magnetic sensing in neurons, the evolution of life reflects ongoing adaptation to geomagnetic field. However, since magnetite-activated, torque-based ion channels within cell membranes have not yet been identified, specialized sensory structures like the semicircular canals might still be necessary for detecting geomagnetic orientation. This mini-review explores the evolution of life from Earth's formation to light-independent human magnetoreception, examining both the magnetite hypothesis and the electromagnetic induction hypothesis as potential mechanisms for human geomagnetic detection.

The cerebral cortex, as the pinnacle of human complexity, poses formidable challenges to contemporary neuroscience. Recent advancements in non-invasive brain stimulation have been pivotal in enhancing human locomotor functions, a burgeoning area of interest in exercise science. Techniques such as transcranial direct current stimulation, transcranial alternating current stimulation, transcranial random noise stimulation, and transcranial magnetic stimulation are widely recognized for their neuromodulator capabilities. Despite their broad applications, these methods are not without limitations, notably in spatial and temporal resolution and their inability to target deep brain structures effectively. The advent of innovative non-invasive brain stimulation modalities, including transcranial focused ultrasound stimulation and temporal interference stimulation technology, heralds a new era in neuromodulation. These approaches offer superior spatial and temporal precision, promising to elevate athletic performance, accelerate sport science research, and enhance recovery from sports-related injuries and neurological conditions. This comprehensive review delves into the principles, applications, and future prospects of non-invasive brain stimulation in the realm of exercise science. By elucidating the mechanisms of action and potential benefits, this study aims to arm researchers with the tools necessary to modulate targeted brain regions, thereby deepening our understanding of the intricate interplay between brain function and human behavior.