Search Results (590)

Ischemic stroke is a multifactorial disease that leads to brain tissue damage and severe neurological deficit. Transient middle cerebral artery occlusion (tMCAO) models are actively used for the molecular, genetic study of stroke. Previously, using high-throughput RNA sequencing (RNA-Seq), we revealed 3774 differentially expressed genes (DEGs) in the penumbra-associated region of the frontal cortex (FC) of rats 24 h after applying the tMCAO model. Here, we studied the gene expression pattern in the striatum that contained an ischemic focus. Striatum samples were obtained from the same rats from which we previously obtained FC samples. Therefore, we compared DEG profiles between two rat brain tissues 24 h after tMCAO. Tissues were selected based on magnetic resonance imaging (MRI) and histological examination (HE) data. As a result, 4409 DEGs were identified 24 h after tMCAO in striatum. Among them, 2609 DEGs were overlapped in the striatum and FC, whereas more than one thousand DEGs were specific for each studied tissue. Furthermore, 54 DEGs exhibited opposite changes at the mRNA level in the two brain tissues after tMCAO. Thus, the spatial regulation of the ischemic process in the ipsilateral hemisphere of rat brain at the transcriptome level was revealed. We believe that the targeted adjustment of the genome responses identified can be the key for the induction of regeneration processes in brain cells after stroke. Full article

Background: Both transcranial direct current stimulation (tDCS) and acupuncture are promising methods for managing chronic low back pain (cLBP), however, their underlying mechanisms remain unclear. Methods: To explore the neural mechanisms of tDCS and acupuncture on cLBP, we examined how real and sham tDCS applied to the bilateral motor cortex (M1), combined with real or sham acupuncture, influenced cerebral blood flow (CBF) using pulsed continuous arterial spin labeling (pCASL) imaging. tDCS was administered over six sessions, combined with real or sham acupuncture, over one month. Results: Following real tDCS, we observed increased CBF in the bilateral occipital cortex, precuneus, left hippocampus, and parahippocampal gyrus/posterior cingulate cortex. After sham tDCS, CBF decreased in regions including the bilateral superior parietal lobule, precuneus, bilateral precentral and postcentral gyri, and left angular gyrus. Real acupuncture led to reduced CBF in the bilateral occipital cortex and hippocampus, and left posterior cingulate gyrus, and increased CBF in the right postcentral gyrus, superior parietal lobule, and frontal areas. Sham acupuncture was associated with decreased CBF in the bilateral hippocampus and anterior cingulate gyrus. Conclusions: These results suggest both shared and distinct patterns of CBF changes between real and sham tDCS, as well as between real and sham acupuncture, reflecting mode-dependent effects on brain networks involved in pain processing and modulation. Our findings highlight the different neural circuits implicated in the therapeutic mechanisms of tDCS and acupuncture in the management of cLBP. Full article

Electroencephalography-based emotion recognition is essential for brain-computer interface combined with artificial intelligence. This paper proposes a novel algorithm for human emotion detection using a hybrid paradigm of convolutional neural networks and a boosting model. The proposed algorithm employs two subsets of 18 and 14 features extracted from four sub-bands using discrete wavelet transform. These features are identified as the optimal subsets of the most relevant, among 42 original input features extracted from two subsets of 8 and 6 productive channels using a dual genetic algorithm combined with a wise-subject 5-fold cross validation procedure in which the first and second genetic algorithms address the efficient channels and optimal feature subsets. The feature subsets are estimated by differently intelligent models and wise-subject 5-fold cross validation procedure on the validation set. The proposed algorithm produces an accuracy of 70.43%/76.05%, precision of 69.88%/74.57%, recall of 98.70%/99.17%, and F1 score of 81.83%/85.13% for valence/arousal classifications, which suggest that the frontal and left regions of the cortex associate especially to human emotions. Full article

There is still a lack of effective therapies for Alzheimer’s disease (AD), the leading cause of dementia and cognitive decline. Identifying reliable biomarkers and therapeutic targets is crucial for advancing AD research. In this study, we developed an aggregative multi-filter gene selection approach to identify AD biomarkers. This method integrates hub gene ranking techniques, such as degree and bottleneck, with feature selection algorithms, including Random Forest and Double Input Symmetrical Relevance, and applies ranking aggregation to improve accuracy and robustness. Five publicly available AD-related microarray datasets (GSE48350, GSE36980, GSE132903, GSE118553, and GSE5281), covering diverse brain regions like the hippocampus and frontal cortex, were analyzed, yielding 803 overlapping differentially expressed genes from 464 AD and 492 normal cases. An independent dataset (GSE109887) was used for external validation. The approach identified 50 prioritized genes, achieving an AUC of 86.8 in logistic regression on the validation dataset, highlighting their predictive value. Pathway analysis revealed involvement in critical biological processes such as synaptic vesicle cycles, neurodegeneration, and cognitive function. These findings provide insights into potential therapeutic targets for AD. Full article

Brain function declines because of aging and several metabolites change their concentration. However, this decrease may be a consequence or a driver of aging. It has been described that taurine levels decrease with age and that taurine supplementation increases health span in mice and monkeys, finding taurine as a driver of aging. The frontal cortex is one of the most key areas studied to know the normal processes of cerebral aging, due to its relevant role in cognitive processes, emotion, and motivation. In the present work, we analyzed by intracerebral microdialysis in vivo in the prefrontal cortex of young (3 months) and old (24 months) awake rats, the basal- and K⁺-evoked release of taurine, and its precursors methionine and serine. The taurine/serine/methionine (TSM) ratio was also calculated as an index of transmethylation reactions. No changes were found in the basal levels of taurine, serine, or methionine between young and aged animals. On the contrary, a significant decrease in the K⁺-evoked release of serine and taurine appeared in aged rats when compared with young animals. No changes were seen in methionine. TSM ratio also decreased with age in both basal- and K⁺-stimulated conditions. Therefore, taurine and its related precursor serine decrease with age in the frontal cortex of aged animals under K⁺-stimulated but not basal conditions, which supports the importance of the decline of evoked taurine in its functions at the brain level, also supporting the idea proposed by other authors of a pharmacological and/or nutritional intervention to its restoration. A deficit of precursors for transmethylation reactions in the brain with age is also considered. Full article

Pathological alterations in Alzheimer’s disease (AD) begin several years prior to symptom onset. Cortical mean diffusivity (cMD) may be used as a measure of early grey matter damage in AD as it reflects the breakdown of microstructural barriers preceding volumetric changes and affecting cognitive function. We investigated cMD changes early in the disease trajectory and evaluated the influence of amyloid-β (Aβ) and tau deposition. In this cross-sectional study, we analysed multimodal PET, DTI, and MRI data of 87 participants, and stratified them into Aβ-negative and -positive, cognitively normal, mildly cognitively impaired, and AD patients. cMD was significantly increased in Aβ-positive MCI and AD compared with CN in the frontal, parietal, temporal cortex, hippocampus, and medial temporal lobe. cMD was significantly correlated with cortical thickness only in patients without Aβ deposition but not in Aβ-positive patients. Our results suggest that cMD is an early marker of neuronal damage since it is observed simultaneously with Aβ deposition and is correlated with cortical thickness only in subjects without Aβ deposition. cMD changes may be driven by Aβ but not tau, suggesting that direct Aβ toxicity or associated inflammation causes damage to neurons. cMD may provide information about early microstructural changes before macrostructural changes. Full article

In amyloid brain PET, after parcellation using the finite element method (FEM)-based algorithm FreeSurfer and voxel-based algorithm PMOD, SUVr examples can be extracted and compared. This study presents the classification SUVr threshold in PET images of F-18 florbetaben (FBB), F-18 flutemetamol (FMM), and F-18 florapronol (FPN) and compares and analyzes the classification performance according to computational algorithm in each brain region. PET images were co-registered after the generated MRI was registered with standard template information. Using MATLAB script, SUVr was calculated using the built-in parcellation number labeled in the brain region. PMOD and FreeSurfer with different algorithms were used to load the PET image, and after registration in MRI, it was normalized to the MRI template. The volume and SUVr of the individual gray matter space region were calculated using an automated anatomical labeling atlas. The SUVr values of eight regions of the frontal cortex (FC), lateral temporal cortex (LTC), mesial temporal cortex (MTC), parietal cortex (PC), occipital cortex (OC), anterior and posterior cingulate cortex (GCA, GCP), and composite were calculated. After calculating the correlation of SUVr using the FreeSurfer and PMOD algorithms and calculating the AUC for amyloid-positive/negative subjects, the classification ability was calculated, and the SVUr threshold was calculated using the Youden index. The correlation coefficients of FreeSurfer and PMOD SUVr calculations of the eight regions of the brain cortex were FBB (0.95), FMM (0.94), and FPN (0.91). The SUVr threshold was SUVr(LTC,min) = 1.264 and SUVr(THA,max) = 1.725 when calculated using FPN-FreeSurfer, and SUVr(MTC,min) = 1.093 and SUVr(MCT,max) = 1.564 when calculated using FPN-PMOD. The AUC comparison showed that there was no statistically significant difference (p > 0.05) in the SUVr classification results using the three radiopharmaceuticals, specifically for the LTC and OC regions in the PMOD analysis, and the LTC and PC regions in the FreeSurfer analysis. The SUVr calculation using PMOD (voxel-based algorithm) has a strong correlation with the calculation using FreeSurfer (FEM-based algorithm); therefore, they complement each other. Quantitative classification analysis with high accuracy is possible using the suggested SUVr threshold. The SUVr classification performance was good in the order of FMM, FBB, and FPN, and showed a good classification performance in the LTC region regardless of the type of radiotracer and analysis algorithm. Full article

Background: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation for treatment-resistant obsessive compulsive disorder (OCD). We aim to compare the treatment outcomes of a newly developed dual-site cathodal tDCS method over the orbitofrontal cortex (OFC) and pre-supplementary motor area (pre-SMA) and two previously reported montages (cerebellum-OFC and pre-SMA) in patients with treatment-resistant OCD. Methods: Eighteen OCD patients were randomly assigned to receive twice-daily 2 mA/20 min sessions for 10 consecutive weekdays, with the active cathode placed on the cerebellum-OFC, bilateral pre-SMA, or OFC-pre-SMA tDCS. The primary outcome was the change in the Yale–Brown Obsessive Compulsive Scale (Y-BOCS). The resting electroencephalogram (EEG) was recorded to obtain the default mode network (DMN) via low-resolution electromagnetic tomography. Each patient received one-week and one-month follow-ups after two weeks of stimulation. Results: At the end of the stimulation, the Y-BOCS scores in the cerebellum-OFC, pre-SMA, and OFC-pre-SMA tDCS groups (n = 6 in each group) were decreased by 14.15 ± 13.31, 7.4 ± 9.59, and 20.75 ± 8.70%, respectively, but no significant differences were found among the groups. In the OFC-pre-SMA tDCS group, OC symptoms significantly decreased by a mean of −20.75% immediately after the 20th tDCS session, and the improvement remained at 1 week and 1 month after tDCS. EEG source functional connectivity analyses revealed increased functional connectivity within the frontal network after OFC-pre-SMA tDCS, whereas decreased functional connectivity within the DMN was observed after cerebellum-OFC tDCS. Conclusions: Dual-site cathodal tDCS over the OFC and pre-SMA might be considered a potential montage to treat patients with treatment-resistant OCD. Future studies using randomized sham-controlled designs are needed. Full article

Background/Objectives: A neurobiological framework of bi- or multilingual neurocognitive development must consider the following: (i) longitudinal behavioral and neural measures; (ii) brain developmental constraints across structure and function; and (iii) the development of global multilingual competence in a homogeneous social environment. In this study, we investigated whether multilingual competence yields early changes in executive attention control mechanisms and their underlying neural structures in the frontal–striatal system, such as the dorsal anterior cingulate cortex/pre-supplemental area and the left caudate. Methods: We employed longitudinal neuroimaging and functional connectivity methods in a small group of multilingual children over two years. Results: We found that the dACC/preSMA is functionally influenced by changes in multilingual competence but not yet structurally adapted, while the left caudate, in a developmental stage, is influenced, adapts, and specializes due to multilingual experience. Furthermore, increases in multilingual competence strengthen connections between the dACC/preSMA, left caudate, and other structures of the cognitive control network, such as the right inferior frontal gyrus and bilateral inferior parietal lobules. Conclusions: These findings suggest that multilingual competence impacts brain “adaptation” and “specialization” during childhood. The results may provide insights and guide future research on experience-expectant and experience-dependent brain plasticity to explain the “interaction” between multilingualism and neurodevelopment. Full article

Microglia are exceptionally dynamic resident innate immune cells within the central nervous system, existing on a continuum of morphologies and functions throughout their lifespan. They play vital roles in response to injuries and infections, clearing cellular debris, and maintaining neural homeostasis throughout development. Emerging research suggests that microglia are strongly influenced by biological factors, including sex, developmental stage, and their local environment. This review synthesizes findings on sex differences in microglial morphology and function in key brain regions, including the frontal cortex, hippocampus, amygdala, hypothalamus, basal ganglia, and cerebellum, across the lifespan. Where available, we examine how gonadal hormones influence these microglial characteristics. Additionally, we highlight the limitations of relying solely on morphology to infer function and underscore the need for comprehensive, multimodal approaches to guide future research. Ultimately, this review aims to advance the dialogue on these spatiotemporally heterogeneous cells and their implications for sex differences in brain function and vulnerability to neurological and psychiatric disorders. Full article

This study investigated the cognitive and neural mechanisms of exact and approximate arithmetic using fNIRS technology during natural calculation processes (i.e., the production paradigm). Behavioral results showed (1) a significantly longer reaction time for exact arithmetic compared to approximate arithmetic, and (2) both exact and approximate arithmetic exhibited a problem size effect, with larger operands requiring more time. The fNIRS results further revealed differences in the neural bases underlying these two arithmetic processes, with exact arithmetic showing greater activation in the L-SFG (left superior frontal gyrus, CH16), while approximate arithmetic exhibited problem size effect in the right hemisphere. Additionally, larger operands registered more brain activities in the R-DLPFC (right dorsolateral prefrontal cortex, CH4), R-SFG (right superior frontal gyrus, CH2), and PMC and SMA (pre- and supplementary motor cortexes, CH3) compared to smaller operands in approximate arithmetic. Moreover, correlation analysis found a significant correlation between approximate arithmetic and semantic processing in the R-PMC and R-SMA (right pre- and supplementary motor cortexes). These findings suggest a neural dissociation between exact and approximate arithmetic, with exact arithmetic processing showing a dominant role in the left hemisphere, while approximate arithmetic processing was more sensitive in the right hemisphere. Full article

Temporal vision is a vital aspect of human perception, encompassing the ability to detect changes in light and motion over time. Optical scattering, or straylight, influences temporal visual acuity and the critical flicker fusion (CFF) threshold, with potential implications for cognitive visual processing. This study investigates how scattering affects CFF using an Arduino-based psychophysical device and electroencephalogram (EEG) recordings to analyze brain activity during CFF tasks under scattering-induced effects. A cohort of 30 participants was tested under conditions of induced scattering to determine its effect on temporal vision. Findings indicate a significant enhancement in temporal resolution under scattering conditions, suggesting that scattering may modulate the temporal aspects of visual perception, potentially by altering neural activity at the temporal and frontal brain lobes. A compensation mechanism is proposed to explain neural adaptations to scattering based on reduced electrical activity in the visual cortex and increased wave oscillations in the temporal lobe. Finally, the combination of the Arduino-based flicker visual stimulator and EEG revealed the excitatory/inhibitory stimulation capabilities of the high-frequency beta oscillation based on the alternation of an achromatic and a chromatic stimulus displayed in the CFF. Full article

Background Chronic stress exposure has been widely recognized as a significant contributor to numerous central nervous system (CNS) disorders, leading to debilitating behavioral changes such as anxiety, depression, and cognitive impairments. The prolonged activation of the hypothalamic–pituitary–adrenal (HPA) axis during chronic stress disrupts the neuroendocrine balance and has detrimental effects on neuronal function and survival. Nelumbo nucifera (N. nucifera) Gaertn., commonly known as the lotus flower, is a traditional medicinal plant consumed for its purported benefits on mental and physical well-being. Despite its traditional use, limited scientific evidence supports these claims. Methods The present study explores the effects of N. nucifera, commonly known as the lotus flower, on cognitive performance and stress resilience in a mouse model subjected to unpredictable chronic mild stress (UCMS). Results Daily treatment significantly improved cognitive performance, alleviated depressive-like behaviors, and normalized hypothalamic–pituitary–adrenal (HPA) axis activity, as indicated by a 60.97% reduction in serum corticosterone. At the molecular level, N. nucifera petals also downregulated serum- and glucocorticoid-inducible kinase 1 (SGK1) mRNA expression while upregulating brain-derived neurotrophic factor (BDNF) mRNA expression and cyclic-adenosine monophosphate (cAMP) responsive element-binding protein (CREB) mRNA expression in the hippocampus and frontal cortex. These normalizations are critical, as chronic stress dysregulates HPA axis function, exacerbating behavioral changes. Furthermore, a phytochemical analysis resulted in the isolation of five major compounds, kaempferol (1), trifolin (2), kaempferol-3-neohesperidoside (3), icariside D₂ (4), and β-sitosterol (5), each demonstrating significant monoamine oxidase (MAO) inhibitory activity. Conclusions These compelling findings suggest that N. nucifera petals not only alleviate stress-induced mood and cognitive deficits but also offer a promising avenue for modulating the HPA axis and promoting neuroprotection via essential neurotrophic factors and enzymatic pathways. We advocate for its potential as a complementary and alternative medicine for effective stress management. Future investigations should further explore its mechanisms of action and evaluate its clinical applicability in stress-related disorders. Full article

Background: Motor imagery includes visual imagery and kinesthetic imagery, which are two strategies that exist for mental rotation and are currently widely studied. However, different mental rotation tests can lead to different strategic performances. There are also many research results where two different strategies appear simultaneously under the same task. Previous studies on the comparative brain mechanisms of kinesthetic imagery and visual imagery have not adopted consistent stimulus images or mature mental rotation paradigms, making it difficult to effectively compare these types of imagery. Methods: In this study, we utilized functional near-infrared spectroscopy (fNIRS) to investigate the brain activation of sixty-seven young right-handed participants with different strategy preferences during hand lateral judgment tasks (HLJT). Results: The results showed that the accuracy of the kinesthetic imagery group was significantly higher than that of the visual imagery group, and the reaction time of the kinesthetic imagery group was significantly shorter than that of the visual imagery group. The areas significantly activated in the kinesthetic imagery group were wider than those in the visual imagery group, including the dorsolateral prefrontal cortex (BA9, 46), premotor cortex (BA6), supplementary motor area (SMA), primary motor cortex (BA4), and parietal cortex (BA7, 40). It is worth noting that the activation levels in the frontal eye fields (BA8), primary somatosensory cortex (BA1, 2, 3), primary motor cortex (BA4), and parietal cortex (BA40) of the kinesthetic imagery group were significantly higher than those in the visual imagery group. Conclusion: Therefore, we speculate that kinesthetic imagery has more advantages than visual imagery in the mental rotation of egocentric transformations. Full article

Retrotransposon Gag-like 4 (RTL4), a gene acquired from a retrovirus, is a causative gene in autism spectrum disorder. Its knockout mice exhibit increased impulsivity, impaired short-term spatial memory, failure to adapt to novel environments, and delayed noradrenaline (NA) recovery in the frontal cortex. However, due to its very low expression in the brain, it remains unknown which brain cells express RTL4 and its dynamics in relation to NA. We addressed these issues using knock-in mice carrying endogenous Rtl4 fused to Venus, which encodes a fluorescent protein. The RTL4-Venus fusion protein was detected as a secreted protein in the midbrain, hypothalamus, hippocampus and amygdala in the postnatal brain. Its signal intensity was high during critical periods of neonatal adaptation to novel environments. It was upregulated by various stimuli, including isoproterenol administration, whereas it was decreased by anesthesia but was maintained by milnacipran administration, suggesting its highly sensitive response to stressors, possible dependence on the arousal state and involvement in the NA reuptake process. In vitro mixed glial culture experiments demonstrated that Rtl4 is a microglial gene and suggested that RTL4 secretion responds rapidly to isoproterenol. Microglial RTL4 plays an important role in the NA response and possibly in the development of the NAergic neuronal network in the brain. Full article