Search Results (190)

Alzheimer’s disease (AD) is characterized by the accumulation of amyloid-β (Aβ) and chronic neuroinflammation, with microglia playing a central role in its pathogenesis. Alterations in microglial metabolism have been proposed to contribute to AD-related inflammatory responses and reduced Aβ clearance, suggesting that thiamine-dependent pathways may be relevant in this context. Thiamine pyrophosphate (TPP), the active form of vitamin B1, is essential for glucose metabolism and mitochondrial function; however, its association with microglial changes in AD remains unclear. In this study, 9-month-old female triple-transgenic AD (3xTg-AD) mice and non-transgenic controls (NoTg) received TPP (2.0 mg/mL) or saline as a vehicle for six weeks via osmotic pumps. Nesting, a hippocampus-dependent behavioral test, as well analyses of Aβ burden, microglial morphology, and the expression of genes related to metabolic and immune pathways were evaluated. Differences in nesting behavior between experimental groups were observed, but TPP treatment was not associated with an evident change in 3xTg-AD mice. In the subiculum and CA1 regions of the hippocampus of female 3xTg-AD mice exposed to TPP, a lower Aβ burden was observed, and morphological variations in microglia were detected in both groups (3xTg-AD and NoTg). Additionally, in the brain of the TPP-treated group, some changes in mRNA gene expression were recorded. Together, these findings describe hippocampal microglial and amyloid profiles following TPP treatment in 3xTg-AD mice and provide a basis for further investigation of thiamine-dependent pathways in AD-related neuroinflammatory contexts. Full article

Background/Objectives: Minor physical anomalies (MPAs) are subtle morphological markers of disrupted neuroectodermal development occurring during early gestation. Their increased prevalence has been reported in several neurodevelopmental and psychiatric conditions, including schizophrenia. However, data on MPAs in pediatric psychosis remain limited. This exploratory descriptive study aimed to characterize the occurrence of MPAs and congenital malformations in children presenting with early-onset psychotic symptoms and to illustrate the clinical heterogeneity through two representative cases. Methods: All participants underwent a comprehensive head-to-toe examination by a trained child and adolescent psychiatrist to identify MPAs. Key anatomical regions, including the face, hair vortex, palate, and extremities, were systematically photographed. Results were corroborated by MRI brain screening and consulted with a clinical geneticist. Anomalies were classified using the standardized Elements of Morphology terminology. Results: Among the 19 study participants, seven (37%) were diagnosed with very early-onset schizophrenia (VEOS). Identified minor physical anomalies included epicanthus (n = 5), café au lait spots (n = 2), and discoloured spots (n = 1). Furthermore, major congenital malformations were detected, specifically Arnold–Chiari malformation type I (n = 1), incomplete hippocampal inversion (n = 1), and a temporal cortex malformation (n = 1). Conclusions: MPAs and selected neuroanatomical anomalies were observed in a subset of children with early-onset psychotic symptoms. While the small sample size and absence of a control group limit interpretability, these exploratory findings suggest that systematic physical examination may provide supportive clinical information in the assessment of pediatric psychosis. Larger, controlled studies are needed to clarify whether specific MPAs may serve as early markers of neurodevelopmental vulnerability. Full article

Background: Glucagon-like peptide-1 receptor (GLP1R) agonists, particularly semaglutide, show neuroprotective effects in genetic models of Alzheimer’s disease (AD). However, their delayed and long-term effects in sporadic AD, such as the intracerebroventricular streptozotocin (STZ) injection, remain insufficient. It is unclear how long the effects of GLP1R agonists persist after discontinuation and whether a single course can suppress progressive neurodegeneration. This study aimed to evaluate the delayed effects of semaglutide administration on morphological changes in neurons and glial cells in the hippocampus associated with cognitive impairment in an STZ-induced rat model of AD. Methods: Rats received bilateral intracerebroventricular STZ injections (3 mg/kg) followed by a 5-week course of intraperitoneal administration of semaglutide (0.1 mg/kg, every other day), and were euthanized 60 days after discontinuation of semaglutide administration. Immunomorphological methods were used to detect neuronal, astrocytic and microglial alterations. A novel object recognition test was performed to assess behavioral effects. Results: STZ-treated animals demonstrated cognitive impairments, ventriculomegaly, a significant increase in p-tau protein fluorescence intensity (p = 0.02), a decrease in CA1–CA3 field area (by 23%, p = 0.008), and reduced hippocampal neuronal density. Decreases in TOMM20 (mitochondrial marker) and synaptophysin levels were accompanied by significant glial activation in the hippocampal CA3 field. Semaglutide administration significantly reduced the enlarged ventricular lumen (by 43.5%), decreased p-tau fluorescence intensity, reduced vimentin-positive reactive astrocytes (by 68.4%), and increased synaptophysin fluorescence intensity. Furthermore, it reduced microglial activation (decreasing IBA1 cell density and elongation) and alleviated the disrupted AQP4 distribution. However, semaglutide did not completely halt the neurodegenerative process and showed no effect on the number of doublecortin-positive cells in the dentate gyrus. Conclusions: Hippocampal changes assessment revealed that course administration of semaglutide exerts prolonged effects, attenuating the severity of pathomorphological alterations and behavioral changes in a sporadic AD model after drug discontinuation. Full article

Primary neuronal cultures from the brain are critical for investigating disease-specific cellular and molecular mechanisms in mouse models. Current methods for obtaining primary cultures require embryonic brains that are affected by embryonic lethality and genotypic characterization in severe disease models such as sickle cell disease (SCD). Furthermore, these neuronal cultures require about 14 days in vitro (DIVs) for neurite outgrowth to mature. We adapted and optimized a relatively simplified and reproducible method using brains from postnatal day 1 mouse pups for isolating and culturing hippocampal and cortical neurons. This approach produces viable neurons that attach, extend neurites, and express key synaptic markers by 7 DIV and also minimizes glial outgrowth. We successfully applied this approach to isolating and culturing hippocampal and cortical neurons from the brains of one-day-old (P1) pups of humanized transgenic homozygous BERK sickle cell and control mice. Morphological observations at 3, 7, and 14 DIVs demonstrated robust neuronal attachment, neurite outgrowth, and overall structural development in both male and female hippocampal and cortical neurons. Neurons in culture expressed key markers including neuronal nuclear protein (NeuN/Rbfox3), neurofilament 200 (NF200), microtubule-associated protein 2 (MAP2), vesicular glutamate transporter 1 (VGLUT1), postsynaptic density protein 95 (PSD 95), and glutamate N-methyl-D-aspartate receptor subunit 2B (GluN2B). Notably, male SCD hippocampal neurons evinced a higher density of PSD 95 puncta on dendritic spines compared to controls on 7 as well as 14 DIVs. Incubation of male hippocampal neurons in a sickle cell-like microenvironment with TNF-α and heme further increased the density of PSD 95 puncta and colocalization of GluN2B with PSD 95, supporting the utility of this culture system for examining disease-relevant structural and molecular responses. This optimized culture system provides a simplified and reproducible platform to investigate the mechanisms involving neuronal dysfunction in challenging mouse models of brain disorders. Full article

Background: Long-term diabetes mellitus may precipitate severe complications, including cognitive dysfunction. Existing research has shown that diabetic cognitive impairment (DCI) in rats is characterized by memory deterioration and a disordered arrangement of hippocampal cells. The Shichangpu–Xiyangshen herb pair (SX) effectively improved the pathological changes induced by DCI. However, the role of SX in regulating the physiological and behavioral responses to DCI remains unclear. Methods: We sought to determine the small-molecule metabolites of cerebrospinal fluid (CSF) and delineate the pathways to elucidate the potential mechanism of the effect of SX in the treatment of DCI by metabolomics strategies, focusing on key mechanisms. Behavioral assessments were conducted on DCI rats and the rats treated with SX, as well as an evaluation of neuronal morphology in the hippocampal region. Metabolomics was used to analyze biomarkers in cerebrospinal fluid at different time points during the development of DCI, to uncover the underlying core mechanisms of DCI, and to investigate the regulatory effects of SX on these core mechanisms. The mechanisms of SX on DCI were investigated using quantitative reverse transcription polymerase chain reaction, immunohistochemistry, Western blot, and ELISA. Results: The Morris water maze (MWM) and social interaction test results revealed that SX administration effectively counteracted cognitive impairments in rats with DCI while simultaneously diminishing pathological damage in the CA1, CA3, and DG hippocampal regions. Further analysis showed that SX restored the significantly reduced levels of IL-8, ROX, and TNF-α, and reduced Aβ plaque formation (as indicated by APP and BACE1 protein expression). Simultaneously, SX markedly ameliorated arachidonic acid metabolic disorders in DCI, including significant reductions in arachidonic acid (AA), PGE2, and LTB4 and reduced expression of COX-2 (PTGS2) and 5-LOX (ALOX-5). Conclusions: Our findings indicate that SX effectively counteracted cognitive impairment in rats with DCI by inhibiting AA metabolism through both cyclooxygenase and lipoxygenase pathways, thereby minimizing neuronal damage. Full article

Chondroitin sulfate (CS) chains are major components of the extra- and pericellular matrix in the central nervous system (CNS), and their sulfation patterns influence CNS development and function. Highly sulfated CS preparations, including CS-D- and CS-E-enriched forms, have been shown to facilitate neurite outgrowth in cultured mouse hippocampal neurons. Notably, neurons cultured on CS-D- or CS-E-enriched substrates exhibited the following distinct morphological characteristics: CS-D promoted the extension of multiple short neurites, whereas CS-E induced the formation of a single elongated neurite with a polarization-like morphology. These features are consistent with early stages of neuronal polarization. However, the specific roles of these highly sulfated CS forms in polarization-like morphology remain unclear. In this study, we demonstrate that polarization-like morphological transitions in hippocampal neurons can be modulated on mixed CS-D/CS-E substrates by varying their ratios. Compared with CS-D-enriched substrates, CS-E-enriched substrates more effectively promoted polarization-like neuronal morphology, accompanied by enhanced activation of Src-family kinases. Furthermore, forced activation of Fyn kinase induced morphological changes resembling polarization-like features in a neuroblastoma cell line, even in the absence of CS-D/CS-E mixed substrates. In conclusion, highly sulfated CS subtypes may function as extracellular cues that regulate neuronal morphology via Src-family signaling, with likely involvement of Fyn. Full article

Background/Objectives: Neuritogenesis and synaptogenesis support learning and cognitive function, and hippocampal neurons play central roles in these processes. Cleistocalyx nervosum var. paniala (CNP), a Southeast Asian berry, has reported neuroprotective activities, but its direct effects on hippocampal neurons remain unclear. We investigated whether CNP extract modulates hippocampal neuronal transcriptomes, neuritogenesis, and synaptogenesis. Methods: Primary hippocampal neurons isolated from male and female Wistar rat pups were treated with CNP extract in vitro. Cytotoxicity was assessed to define non-cytotoxic concentrations. Transcriptomic responses were profiled by RNA sequencing and validated by RT-qPCR. Neuritogenesis was quantified by neurite morphology and Sholl analysis. Synaptogenesis was evaluated by synaptic immunocytochemistry. Molecular docking of cyanidin-3-glucoside (C3G) and resveratrol was used to generate mechanistic hypotheses. Results: At 0.1–10 µg/mL, CNP was non-cytotoxic, whereas a 100 µg/mL dose reduced viability; therefore, 10 µg/mL was used in subsequent experiments. Exploratory RNA-seq profiling identified thousands of differentially expressed genes enriched in synapse- and neurite-related pathways, including synaptogenesis signaling, axon guidance, and neuritogenesis. RT-qPCR showed upregulation of Igf1 in males and Glul in females, with sex-dependent modulation of Bdnf and Cask. CNP increased neurite length, branching, and Sholl complexity in both sexes, with a more pronounced effect in males. A male-biased effect was also observed in synapse-related marker colocalization, with increased Syn1–Psd95 colocalization detected in males. Docking suggested plausible interactions of C3G and resveratrol with regulators such as MYC, TP53, and CREB1. Conclusions: CNP extract alters transcriptional networks and enhances neurite outgrowth in primary hippocampal neurons in a sex-dependent manner, with male-biased effects on Syn1–Psd95 colocalization. These findings support further dose–response, mechanistic, and sex-stratified in vivo studies to evaluate its neurobiological potential. Full article

The etiology of autism spectrum disorder (ASD) implicates genetic predispositions and environmental chemicals, such as polybrominated diphenyl ethers (PBDEs). We aimed to identify whether mitochondrial quality control (MQC) was involved in ASD-relevant behavioral changes induced by decabromodiphenyl ether (deca-BDE, BDE-209) and the alleviation by melatonin. Pregnant rats exposed to BDE-209 (50 mg/kg i.g.) were administrated melatonin through drinking water (0.2 mg/mL) during gestation and lactation. Behavioral assessments integrated open-field test, three-chamber social test, and Morris water maze; mitochondrial detections took transmission electron microscopy, immunofluorescence, and homeostasis together; hippocampal molecular network was identified through transcriptomics profiles, combining dendritic morphology analysis after Golgi-Cox staining. Melatonin supplementation attenuated BDE-209-reduced social and cognitive ability, accompanied by improvements in hippocampal synaptic plasticity (dendritic spines, PSD95, SNAP25). Mitochondrial dysfunctions, shown as decreases in complex IV activity, ATP content, and mtDNA copies, plus redox imbalance (ROS/SOD2) and resultant mitochondrial membrane potential disruption and apoptosis, together with fusion/fission dynamic (MFN2/DRP1), biogenesis (SIRT1-PGC1α-TFAM), and mitophagy (SIRT3-FOXO3-PINK1) suppression, were reversed by melatonin partially through SIRT1 (Sirtuin-1)-dependent pathways, as these protections were abolished by inhibitor EX527. This study highlighted the SIRT1–SIRT3 axis in MQC and behavioral effects, providing novel intervention for PBDEs’ neurodevelopmental impairment. Full article

(1) Background: Adult neurogenesis within the hippocampus modulates hippocampal memory and is often dysregulated in diseases that cause memory dysfunction, notably Alzheimer’s disease. We have discovered a novel modulator of hippocampal neurogenesis—low-density lipoprotein receptor-related protein 1 (LRP1). (2) Methods: Using an inducible knockout of LRP1, male and female mice were subject to loss of LRP1, specifically in adult-born neural stem cells at 3 months of age. (3) Results: After 6 months with the knockout, animals without LRP1 in adult-born neural stem cells displayed behavioral phenotypes consistent with deficits in working memory and hippocampal-mediated spatial memory. We also found that over time, increasing numbers of adult-born LRP1-knockout neurons were present, although those neurons were morphologically less complex with fewer dendrites than controls. Our data suggest that the increase in the total number of adult-born neurons 6 months after knockout is due to a subtle increase in hippocampal proliferation over time. (4) Conclusions: Altogether, our data suggest that LRP1 is an important and previously unknown regulator of hippocampal neurogenesis. Full article

Background/Objectives: Systemic inflammation is a known driver of neurodegenerative processes, with amyloid accumulation and neuronal loss. The Interleukin-33 (IL-33)/Suppression of Tumorigenicity 2 (ST2) signaling pathway has emerged as a critical immune regulator with dual roles in maintaining brain health. However, its role in pathological alterations in the central nervous system, and more specifically in the hippocampus during endotoxemia, is not fully elucidated. The aim of this research was to determine the role of the IL-33/ST2 axis in neurodegenerative processes in mice caused by systemic inflammation. Methods: BALB/c wild-type (WT) and ST2-deficient (ST2^−/−) mice were challenged with systemic lipopolysaccharide (LPS) for 7 days. One subgroup of WT mice also received exogenous IL-33. Expression of Iba1, myelin, and amyloid was detected by immunohistochemistry, the TUNEL assay was used for detection of apoptosis, flow cytometry was used to assess microglial phenotype, and RT PCR was used to detect the expression of cytokines. Results: LPS administration induced demyelination and amyloid deposition in the hippocampus. These pathological changes were the most pronounced in ST2^−/− mice, which exhibited an aggressive microglial phenotype, excessive production of IL-1β and massive apoptosis in the hippocampus. Conversely, exogenous IL-33 treatment in WT mice exerted a profound neuroprotective effect. IL-33 induced phagocytic morphology of Iba1-positive cells, redirected microglia toward a restorative M2 phenotype, and significantly upregulated IL-10. This immunomodulation led to the preservation of myelin integrity, a reduction in amyloid load, and the near-complete prevention of hippocampal apoptosis in IL-33 treated mice. Conclusions: This study identifies the IL-33/ST2 axis as an important defense signaling pathway in neuroinflammation induced by systemic LPS administration. By promoting a regulatory microglial state and balancing the IL-10/IL-1β ratio, IL-33 prevents neuroinflammation and neurodegeneration. Our data highlight the pharmacological potential of the IL-33/ST2 axis in counteracting amyloid-related pathologies. Full article

Background: After imipenem was introduced in clinical practice, neurologic adverse effects led to recommendations against its use in patients with neurologic conditions. However, these conclusions were drawn without considering pharmacokinetic variations in such patients. Furthermore, animal studies lack the use of clinically relevant doses and supporting morphological studies in both naïve and disease models. Objectives: We aim to study the effects of imipenem in the hippocampus of naïve animals, evaluating potential behavioral and morphological alterations. Methods: Naïve Wistar rats received a 10-day course of intraperitoneal imipenem (40 mg/kg) while controls received a saline injection. After that, they were put through the Morris water maze, elevated plus maze, open-field test, and then euthanized. We analyzed neurogenesis (using doublecortin immunoreactivity), astrogliosis, and the γ-Aminobutyric acid (GABA)ergic system (using parvalbumin (PV), calretinin (CR) and calbindin (CB) immunoreactive (IR) neurons) in the hippocampus. Results: Interestingly, our results showed no significant alterations in both short and long-term memory, nor in anxiety. There were also no significant changes in the neuronal density of doublecortin-immunoreactive (IR) neurons nor in astrogliosis. Furthermore, the areal density of PV- and CR-IR was preserved in all hippocampal subfields. The density of CB-IR neurons also showed no changes in the dentate gyrus, CA3, and subiculum; however, a significant increase was found in the CA1 region. Conclusions: Our results indicate that in naïve individuals, a clinically relevant dose of imipenem does not seem to cause overt behavioral deficits or widespread morphological alterations in the hippocampus. However, a specific increase in the CB-IR neuronal population in the CA1 region highlights a localized cellular alteration/plasticity induced by the imipenem. Hence, pharmacokinetic factors seem to be the potential contributors of imipenem side effects. Further studies should focus on this as a possible cause and focus on individuals with brain diseases. Full article

Taurine is a free amino acid with various effects, such as developing the nervous system, an immune function, an antioxidative effect, enhancing muscle and cardiovascular function, and reducing fatigue. In this study, we investigated the effect of taurine supplementation on ischemic neuronal damage in the hippocampus of gerbils. Taurine (150 mg/kg) was orally administered to gerbils before and after induction of transient ischemia. Histologically, we examined surviving and degenerating neurons by neuronal nuclei immunostaining and fluoro-jade C (FJC) staining. Gliosis was morphologically confirmed by GFAP and Iba1 immunostaining. Compared to the ischemia and pre-treated gerbils, pre- and post-taurine supplementation was neuroprotective by maintaining higher number of mature NeuN-immunoreactive neurons and reducing neuronal death (FJC-stained cells) in the hippocampal CA1 region. Additionally, the ischemia-induced reactive astrocytosis and microgliosis was significantly mitigated by long-term taurine treatment in the gerbil hippocampus. Furthermore, we confirmed that pre- and post-taurine supplementation downregulated ischemia-mediated induction in the MAPK cascade, such as ERK, JNK, and p38, which are involved in oxidative stress, inflammation, apoptosis, and cell differentiation, and this treatment upregulated an ischemia-mediated reduction in antioxidants such as SOD2, GPX4, and anti-apoptotic factor Bcl-2 in the gerbil hippocampus. Pre- and post-taurine supplementation also downregulated again the ischemic injury-mediated activation of transcriptional factor NFkβ, an important gene expression regulator, especially in the inflammatory response, and pro-apoptotic factor Bax in the gerbil hippocampus. Our present results suggest that pre- and post-taurine supplementation has potential in neuroprotection against ischemia-induced neuronal death and glial activation by attenuating oxidative stress and apoptosis. Full article

Background/Objectives: Empagliflozin (EMPA) was repurposed for Alzheimer’s disease (AD) treatment via buccal delivery, exploiting novel nanofibers (NFs) integrating chitosan (Cs), silk fibroin (Fb), and poly(lactic acid) (PLA). Methods: EMPA-loaded Cs/Fb/PLA NFs were electrospun in different formulations to optimize the formulation parameters. The optimized formulation was then investigated for its enhanced in vivo effect. Results: Optimized nanofiber diameters ranged from 459 ± 173 to 668 ± 148 nm, possessing bead-free morphology confirmed by SEM and satisfactory mechanical properties. EMPA was successfully well-dispersed in the polymer matrix as evidenced by FTIR, XRD, and drug content. The optimized NFs displayed a hydrophilic surface (contact angle < 90°), and biphasic drug release with sustained EMPA liberation (84.98% over 24 h). In vivo, buccal EMPA-Cs/Fb/PLA NFs in an AlCl₃-induced AD rat model significantly reduced brain-amyloid-β, phosphorylated tau, IL-1β, and AGER expression by 2.88-, 2.64-, 2.87-, and 2.50-fold, respectively, compared to positive controls, and improved locomotor activity (1.86-fold) and cognitive performance (T-maze) (4.17-fold). Compared to pure EMPA, the nanofiber formulation achieved further reductions in amyloid-β (1.78-fold), p-tau (1.42-fold), IL-1β (1.89-fold), and AGER (1.38-fold), with efficacy comparable to memantine. Histopathological examination revealed preservation of the hippocampal neuronal structure. Conclusions: The findings suggest EMPA-loaded Cs/Fb/PLA NFs as a promising non-invasive, sustained-release buccal delivery platform for AD therapy, offering multimodal neuroprotection through modulation of the Aβ–AGER–p-tau axis. Full article

Mild traumatic brain injury (mTBI) disrupts hippocampal network function through coordinated alterations in glial reactivity, synaptic integrity, and adult neurogenesis. Effective therapeutic approaches targeting these interconnected processes remain limited. Lipid-derived molecules capable of modulating these mTBI-induced disturbances are emerging as promising neuroprotective candidates. Here, we investigated the effects of N-stearidonylethanolamine (SDEA), an ω-3 ethanolamide, in a mouse model of mTBI. SDEA treatment attenuated astrocytic reactivity, restored Arc expression, and improved dendritic spine density and morphology in the CA1 hippocampal area. In the dentate gyrus, mTBI reduced Ki-67-indexed proliferation while leaving DCX-positive immature neurons unchanged, and SDEA partially rescued proliferative activity. These effects were accompanied by improvements in anxiety-like behavior and working-memory performance. Together, these findings demonstrate that SDEA modulates several key components of the glia-synapse-neurogenesis axis and supports functional recovery of hippocampal circuits following mTBI. These results suggest that ω-3 ethanolamides may represent promising candidates for multi-target therapeutic strategies in mTBI. Full article

Temporal lobe epilepsy (TLE), the most common form of epilepsy, is often resistant to symptomatic treatment and characterized by persistent neuroinflammation, creating an urgent need for therapeutic strategies that can modulate early disease mechanisms. In this study, we examined the ability of the human MSC-derived secretome to influence epileptic hippocampal tissue during the latent phase of epileptogenesis using an ex vivo model. For this purpose, we characterized the MSC-derived secretome using multiplex Luminex profiling, optimized organotypic hippocampal cultures (OHCs) by evaluating cell viability, validated the pilocarpine-induced TLE model both morphologically and electrophysiologically, and investigated the influence of MSC-conditioned medium (MSC-CM) on epileptic hippocampal tissue. Using mouse-derived OHCs, we found that MSC-CM supports the preservation of nestin- and doublecortin (DCX)-positive progenitor cells, reduces NF-κB (p50/p105) levels, decreases LDH release into the culture medium, and modulates IL-6 secretion during the latent phase of epileptogenesis. Taken together, these findings suggest that the MSC-derived secretome exerts cytoprotective and context-dependent immunomodulatory effects, attenuating inflammatory signaling and cellular stress while supporting the preservation of neural progenitor markers in epileptic tissue. These properties highlight a potential phase-specific therapeutic window to modulate pathological processes during the latent phase of epileptogenesis. Full article