Search Results (7,307)

Background: Toxoplasma gondii is a globally widespread parasite responsible for toxoplasmosis, a zoonotic disease with significant impact on both human and animal health. The current lack of safe and effective treatments underscores the need for new drugs. Earlier, thiosemicarbazones (TSCs) and their metal complexes have shown promising activities against T. gondii. This study evaluated a gold (III) complex C3 and its TSC ligand C4 for safety in host immune cells and zebrafish embryos, followed by efficacy assessment in a murine model for chronic toxoplasmosis. Methods: The effects on viability and proliferation of murine splenocytes were determined using Alamar Blue assay and BrdU ELISA, and potential effects of the drugs on zebrafish (Danio rerio) embryos were detected through daily light microscopical inspection within the first 96 h of embryo development. The parasite burden in treated versus non-treated mice was measured by quantitative real-time PCR in the brain, eyes and the heart. Results: Neither compound showed immunosuppressive effects on the host immune cells but displayed dose-dependent toxicity on early zebrafish embryo development, suggesting that these compounds should not be applied in pregnant animals. In the murine model of chronic toxoplasmosis, C4 treatment significantly reduced the parasite load in the heart but not in the brain or eyes, while C3 did not have any impact on the parasite load. Conclusions: These results highlight the potential of C4 for further exploration but also the limitations of current approaches in effectively reducing parasite burden in vivo. Full article

Among the numerous compounds released as a result of human activities, endocrine-disrupting chemicals (EDCs) have attracted particular attention due to their widespread detection in human biological samples and their accumulation across various ecosystems. While early research primarily focused on their effects on reproductive health, it is now evident that EDCs may impact neurodevelopment, altering the integrity of neural circuits essential for cognitive abilities, emotional regulation, and social behaviors. These compounds may elicit epigenetic modifications, such as DNA methylation and histone acetylation, that result in altered expression patterns, potentially affecting multiple generations and contribute to long-term behavioral phenotypes. The effects of EDCs may occur though both direct and indirect mechanisms, ultimately converging on neurodevelopmental vulnerability. In particular, the gut–brain axis has emerged as a critical interface targeted by EDCs. This bidirectional communication network integrates the nervous, immune, and endocrine systems. By altering the microbiota composition, modulating immune responses, and triggering epigenetic mechanisms, EDCs can act on multiple and interconnected pathways. In this context, elucidating the impact of EDCs on neurodevelopmental processes is crucial for advancing our understanding of their contribution to neurological and behavioral health risks. Full article

Concept-cognitive learning reveals the principle of human cognition by simulating the brain’s process of learning and processing concepts. Nevertheless, for neighborhood similarity granules, the average information of objects regarding all attributes is not considered, which may lead to unbalanced acquisition of knowledge. On the other hand, there are some unnecessary concepts in the extension of fuzzy concepts, which results in poor classification learning. To tackle these challenges, we present a forgetting-based concept-cognitive learning model for classification in a fuzzy formal decision context. Firstly, the fuzzy concept space is established based on the the correlation coefficient matrix. Then, to delete unnecessary objects that are in the zone of proximal development, we construct the forgetting fuzzy concept space by selecting the concept corresponding to the maximum similarity. Subsequently, a forgetting-based fuzzy concept model (FCCLM) mechanism is proposed. In the end, experimental results on eight datasets validate the feasibility and efficiency of the proposed learning mechanism through classification performance assessment. Full article

Background/Objectives: Solanezumab is a humanized monoclonal antibody designed to bind soluble amyloid-beta (Aβ) and facilitate its clearance from the brain, aiming to slow the progression of Alzheimer’s disease (AD). Methods: A systematic search was applied in four medical databases through October 2024 to identify phase 2 or 3 randomized controlled trials evaluating solanezumab in patients aged ≥50 years with mild AD or in preclinical stages. The primary outcomes were changes in cognitive and functional scales, including ADAS-cog14, MMSE, ADCS-ADL, and CDR-SB. Data were pooled using a random-effects model, and certainty of evidence was assessed using GRADE. Results: Seven trials involving 4181 participants were included. Solanezumab did not significantly reduce cognitive decline based on ADAS-cog14 (MD = −0.75; 95% CI: −2.65 to 1.15; very low certainty) or improve functional scores on ADCS-ADL (MD = 0.85; 95% CI: −1.86 to 3.56; very low certainty) and CDR-SB (MD = −0.15; 95% CI: −0.89 to 0.60; very low certainty). A modest but statistically significant improvement was observed in MMSE scores (MD = 0.59; 95% CI: 0.33 to 0.86; moderate certainty). Conclusions: While solanezumab may offer slight benefits in general cognitive performance, its overall impact on clinically meaningful outcomes remains limited. The results do not support its use as a disease-modifying therapy for Alzheimer’s disease in either preclinical or symptomatic stages. Full article

Background/Objectives: Autism spectrum disorder (ASD) has been extensively studied through neuroimaging, primarily focusing on grey matter and more in children than in adults. Studies in children and adolescents fail to capture changes that may dampen with age, thus leaving only changes specific to ASD. While grey matter has been the primary focus, white matter (WM) may be more specific in identifying the particular biological signature of the neurodiversity of ASD. Diffusion tensor imaging (DTI) is the more appropriate tool to investigate WM in ASD. Despite being introduced in 1994, its application to ASD research began in 2001. Studies employing DTI identify altered fractional anisotropy (FA), mean diffusivity, and radial diffusivity (RD) in individuals with ASD compared to typically developing (TD) individuals. Methods: We systematically reviewed literature on 21 May 2025 on PubMed using the following strategy: (“autism spectrum”[ti] OR autistic[ti] OR ASD[ti] OR “high-functioning autism” OR Asperger*[ti] OR Rett*[ti]) AND (DTI[ti] OR “diffusion tensor”[ti] OR multimodal[ti] OR “white matter”[ti] OR tractograph*[ti]). Our search yielded 239 results, of which 26 were adult human studies and eligible. Results: Analysing the evidence, we obtained regionally diverse WM alterations in adult ASD, specifically in FA, MD, RD, axial diffusivity and kurtosis, neurite density, and orientation dispersion index, compared to TD individuals, mostly in frontal and interhemispheric tracts, association fibres, and subcortical projection pathways. These alterations were less prominent than those of children and adolescents, indicating that individuals with ASD may improve during brain maturation. Conclusions: Our findings suggest that white matter alterations in adults with ASD are regionally diverse but generally less pronounced than in younger populations. This may indicate a potential improvement or adaptation of brain structure during maturation. Further research is needed to clarify the neurobiological mechanisms underlying these changes and their implications for clinical outcomes. Full article

Background/Objectives: An important new consideration when studying autism spectrum disorder (ASD) is the bioenergetic mechanisms underlying the relatively recent rapid evolutionary expansion of the human brain, which pose fundamental risks for mitochondrial dysfunction and calcium signaling abnormalities and their potential role in ASD, as recently highlighted by insights from the BTBR mouse model of ASD. The rapid brain expansion taking place as Homo sapiens evolved, particularly in the parietal lobe, led to increased energy demands, making the brain vulnerable to such metabolic disruptions as are seen in ASD. Methods: Mitochondrial dysfunction in ASD is characterized by impaired oxidative phosphorylation, elevated lactate and alanine levels, carnitine deficiency, abnormal reactive oxygen species (ROS), and altered calcium homeostasis. These dysfunctions are primarily functional, rather than being due to mitochondrial DNA mutations. Calcium signaling plays a crucial role in neuronal ATP production, with disruptions in inositol 1,4,5-trisphosphate receptor (ITPR)-mediated endoplasmic reticulum (ER) calcium release being observed in ASD patient-derived cells. Results: This impaired signaling affects the ER–mitochondrial calcium axis, leading to mitochondrial energy deficiency, particularly in high-energy regions of the developing brain. The BTBR mouse model, with its unique Itpr3 gene mutation, exhibits core autism-like behaviors and metabolic syndromes, providing valuable insights into ASD pathophysiology. Conclusions: Various interventions have been tested in BTBR mice, as in ASD, but none have directly targeted the Itpr3 mutation or its calcium signaling pathway. This review presents current genetic, biochemical, and neurological findings in ASD and its model systems, highlighting the need for further research into metabolic resilience and calcium signaling as potential diagnostic and therapeutic targets for ASD. Full article

Background/Objectives: Epilepsy is a brain condition that affects millions of people worldwide. Although there are many antiepileptic drugs with different mechanisms of action, many patients still fail to control their agonizing symptoms, a situation that highlights the need for more strategies to address this issue. In this in vitro study, we elucidated and characterized the alterations in intracellular Ca²⁺ levels in cell cultures where diazepam and repetitive transcranial magnetic stimulation were implemented, alone or in combination. Methods: Using the differentiated human-derived neuroblastoma cell line SH-SY5Y, we measured the alterations in intracellular Ca²⁺ levels under the impact of either low-frequency repetitive transcranial magnetic stimulation (1 Hz), diazepam (14 μM), or their combination. We used the Ca²⁺-sensitive fluorescent indicator Fluo-4 acetoxymethyl ester for calcium imaging, while neuronal excitation was achieved with 50 mM KCl. Results: The highest median fluorescence intensity increase (%ΔF/F = 24.80) was observed in control cell cultures, followed by rTMS cultures (%ΔF/F = 16.96) and diazepam cultures (%ΔF/F = 11.46). The lowest median fluorescence intensity value (%ΔF/F =−0.44) was observed when diazepam was used concomitantly with repetitive transcranial magnetic stimulation. Post hoc analysis assessed pairwise differences, showing statistically significant differentiation between the control group and all other groups. Additionally, statistically significant results were observed between repetitive transcranial magnetic stimulation or diazepam and their combination, but not between them. Conclusions: The combination of diazepam and repetitive transcranial magnetic stimulation resulted in the most significant reduction in intracellular Ca²⁺ levels, as indicated by the lowest fluorescence values compared with the control group. Individually, each treatment produced a notable but less pronounced effect. We conclude that both diazepam and low-frequency repetitive transcranial magnetic stimulation can control epileptiform activity in vitro, while their combination is the most effective treatment. Full article

Miller–Dieker Syndrome (MDS) is a rare neurodevelopmental disorder caused by a heterozygous deletion of approximately 26 genes within the MDS locus of human chromosome 17. MDS, which affects 1 in 100,000 babies, can lead to a range of phenotypes, including lissencephaly, severe neurological defects, distinctive facial abnormalities, cognitive impairments, seizures, growth retardation, and congenital heart and liver abnormalities. One hallmark feature of MDS is an unusually smooth brain surface due to abnormal neuronal migration during early brain development. Several genes located within the MDS locus have been implicated in the pathogenesis of MDS, including PAFAH1B1, YWHAE, CRK, and METTL16. These genes play a role in the molecular and cellular pathways that are vital for neuronal migration, the proper development of the cerebral cortex, and protein translation in MDS. Improved model systems, such as MDS patient-derived organoids and multi-omics analyses indicate that WNT/β-catenin signaling, calcium signaling, S-adenosyl methionine (SAM) homeostasis, mammalian target of rapamycin (mTOR) signaling, Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling, and others are dysfunctional in MDS. This review of MDS integrates details at the clinical level alongside newly emerging details at the molecular and cellular levels, which may inform the development of novel therapeutic strategies for MDS. Full article

Adipose stem cells (ASCs) are a subset of mesenchymal stem cells with validated immunomodulatory and regenerative capabilities that make them attractive tools for treating neurodegenerative disorders, such as multiple sclerosis (MS). Several studies conducted on experimental autoimmune encephalomyelitis (EAE), the animal model of MS, have clearly shown a therapeutic effect of ASCs. However, controversial data on their efficacy were obtained from I- and II-phase clinical trials in MS patients, highlighting standardization issues and limited data on long-term safety. In this context, ASC-derived extracellular vesicles from (ASC-EVs) represent a safer, more reproducible alternative for EAE and MS treatment. Moreover, their physical characteristics lend themselves to a non-invasive, efficient, and easy handling of intranasal delivery. Using an in vitro setting, we first verified ASC-EVs’ ability to cross the human nasal epithelium under an inflammatory milieu. Magnetic resonance corroborated these data in vivo in intranasally treated MOG35-55-induced EAE mice, showing a preferential accumulation of ASC-EVs in brain-inflamed lesions compared to a stochastic distribution in healthy control mice. Moreover, intranasal treatment of ASC-EVs at the EAE onset led to a long-term therapeutic effect using two different experimental protocols. A marked reduction in T cell infiltration, demyelination, axonal damage, and cytokine production were correlated to EAE amelioration in ASC-EV-treated mice compared to control mice, highlighting the immunomodulatory and neuroprotective roles exerted by ASC-EVs during EAE progression. Overall, our study paves the way for promising clinical applications of self-administered ASC-EV intranasal treatment in CNS disorders, including MS. Full article

Neuroinflammation is a key feature of Alzheimer’s disease (AD), and stem cell therapies have emerged as promising candidates due to their immunomodulatory properties. Neuro-Cells (NC), a combination of unmodified mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs), have demonstrated therapeutic potential in models of central nervous system (CNS) injury and neurodegeneration. Here, we studied the effects of NC in APPswe/PS1dE9 mice, an AD mouse model. Twelve-month-old APPswe/PS1dE9 mice or their wild-type littermates were injected with NC or vehicle into the cisterna magna. Five to six weeks post-injection, cognitive, locomotor, and emotional behaviors were assessed. The brain was stained for amyloid plaque density using Congo red, and for astrogliosis using DAPI and GFAP staining. Gene expression of immune activation markers (Il-1β, Il-6, Cd45, Tnf) and plasticity markers (Tubβ3, Bace1, Trem2, Stat3) was examined in the prefrontal cortex. IL-6 secretion was measured in cultured human monocytes following endotoxin challenge and NC treatment. Untreated APPswe/PS1dE9 mice displayed impaired learning in the conditioned taste aversion test, reduced object exploration, and anxiety-like behavior, which were improved in the NC-treated mutants. NC treatment normalized the expression of several immune and plasticity markers and reduced the density of GFAP-positive cells in the hippocampus and thalamus. NC treatment decreased amyloid plaque density in the hippocampus and thalamus, targeting plaques of <100 μm². Additionally, NC treatment suppressed IL-6 secretion by human monocytes. Thus, NC treatment alleviated behavioral deficits and reduced amyloid plaque formation in APPswe/PS1dE9 mice, likely via anti-inflammatory mechanisms. The reduction in IL-6 production in human monocytes further supports the potential of NC therapy for the treatment of AD. Full article

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

The Notch signaling pathway is a critical regulator of embryonic brain development. Among its four mammalian receptors, Notch1 and Notch2 are particularly significant in the developing cortex, yet their roles in human neurodevelopment are not well understood. In murine cortex development, Notch1 primarily regulates early progenitor identity and neurogenesis, while Notch2 is required for maintaining radial glial cells at later stages. However, it is unclear whether these functions are conserved in the human developing brain. In this study, we used cerebral organoids as an in vitro model of early human corticogenesis and conducted lentiviral shRNA-mediated knockdowns of NOTCH1 and NOTCH2. Our findings indicate that NOTCH1 is essential for organoid growth, lumen morphogenesis, radial glial identity, and progenitor proliferation. In contrast, depleting NOTCH2 did not significantly affect these early developmental processes. These results demonstrate that NOTCH1 and NOTCH2 have potentially non-redundant and temporally distinct roles in early human corticogenesis, reflecting receptor-specific specialization within the Notch signaling pathway. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder primarily characterized by memory loss, cognitive decline, and structural brain atrophy. Substantial sex differences have been observed in its incidence, clinical trajectory, and response to treatment. Women are disproportionately affected, exhibiting faster progression and more severe cognitive impairment. Exercise has emerged as a promising non-pharmacological intervention to mitigate AD-related decline, yet growing evidence reveals that its benefits vary by sex. This review synthesizes current findings from human and animal studies, focusing on how exercise impacts AD differently in males and females. In women, exercise is more strongly associated with improvements in cognitive function, neurotrophic support, and emotional regulation. In men, benefits tend to involve structural preservation and oxidative adaptations. Underlying mechanisms include differential hormonal profiles, inflammatory responses, and neuroplastic signaling pathways. These findings underscore the need to consider sex as a biological variable in AD research. Developing sex-specific exercise strategies may enhance therapeutic outcomes and support more individualized approaches in AD prevention and care. Full article

Reinforcement learning models often rely on uncertainty estimation to guide decision-making in dynamic environments. However, the role of memory limitations in representing statistical regularities in the environment is less understood. This study investigated how limited memory capacity influence uncertainty estimation, potentially leading to misestimations of outcomes and environmental statistics. We developed a computational model incorporating active working memory processes and lateral inhibition to demonstrate how relevant information is selected, stored, and used to estimate uncertainty. The model allows for the detection of contextual changes by estimating expected uncertainty and perceived volatility. Two experiments were conducted to investigate limitations in information availability and uncertainty estimation. The first experiment explored the effect of cognitive load on memory reliance for uncertainty estimation. The results show that cognitive load diminished reliance on memory, lowered expected uncertainty, and increased perceptions of environmental volatility. The second experiment assessed how outcome exposure conditions affect the ability to detect environmental changes, revealing differences in the mechanisms used for environmental change detection. The findings emphasize the importance of memory constraints in uncertainty estimation, highlighting how misestimation of uncertainties is influenced by individual experiences and the capacity of working memory (WM) to store relevant information. These insights contribute to understanding the role of WM in decision-making under uncertainty and provide a framework for exploring the dynamics of reinforcement learning in memory-limited systems. Full article

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant widely used in consumer products. TBBPA is often detected in soil, water, organisms, and even in human blood and breast milk. Hence, it is accessible to developing fetuses and nursing offspring after maternal exposure. The reported evidence for the endocrine disruption of TBBPA in the brain has raised concerns regarding its effects on neurodevelopmental and behavioral functions. This study investigated the effects of TBBPA exposure on neurodevelopment. A cell-based developmental neurotoxicity assay was performed to determine whether TBBPA is a developmental neurotoxicant. The assay revealed TBBPA to be a developmental neurotoxicant. C57BL/6N maternal mice were administered TBBPA at 0, 0.24, and 2.4 mg/kg during pregnancy and lactation, and their offspring underwent behavioral testing. The behavioral experiments revealed sex-specific effects. In females, only a deterioration of the motor ability was observed. In contrast, deteriorations in motor function, memory, and social interaction were noted in males. Furthermore, we validated changes in the expression of genes associated with behavioral abnormalities, confirming that perinatal exposure to TBBPA, at the administered doses, can affect neurodevelopment and behavior in offspring. These findings highlight the need for more in-depth and multifaceted research on the toxicity of TBBPA. Full article