Glyceryl tribenzoate (GTB) or tribenzoin is a flavoring agent with characteristic anti-microbial property. We have already delineated GTB's immunomodulatory role via the enrichment of regulatory T cells in mouse models of multiple sclerosis and anti-neuroinflammatory role via the reduction of glial activation in a monkey model of Parkinson's disease and a mouse model of Huntington's disease. However, its role has never been explored in Alzheimer's disease (AD), the most common neurodegenerative disorder in human. This study underlines the importance of GTB in promoting the growth and function of hippocampal neurons via upregulation of plasticity-associated genes, enrichment of dendritic spines and stimulation of inotropic calcium influx. Accordingly, oral GTB improved hippocampal plasticity and protected memory and learning in 5xFAD mice. Similarly, GTB treatment also reduced cerebral plaque load and increased the life span of aged 5xFAD mice. Interestingly, we observed that peroxisome proliferator-activated receptor alpha (PPARα), a nuclear hormone receptor, served as a receptor of GTB. Consequently, GTB was shown to improve hippocampal plasticity and increase cognitive functions in 5xFAD, but not 5xFAD/Ppara-null, mice, indicating an important role of PPARα in GTB-mediated neuroprotection. These results suggest that oral GTB may have therapeutic importance for improving hippocampal functions in AD patients.

Motion sickness (MS) is a prevalent and debilitating vestibular disorder with limited therapeutic options, yet the cortical mechanisms governing individual susceptibility remain elusive. Using a biaxial rotation mouse model, we investigated the role of the anterior cingulate cortex (ACC) in MS by integrating morphology, calcium imaging, electrophysiology, cell ablation, chemogenetics, and optogenetics. Biaxial rotation induced hypothermia, anorexia, taste avoidance, locomotor hypoactivity, and gait incoordination. ACC pyramidal neurons exhibited enhanced activation and increased intrinsic excitability following vestibular stimulation. Ablation of ACC CaMKII[+] neurons alleviated MS symptoms, and bidirectional chemogenetic manipulation demonstrated that ACC glutamatergic projection neurons are both necessary and sufficient for MS behaviors. Furthermore, the ACC to medial vestibular nuclei parvicellular part (MVePC) projection was identified as a previously uncharacterized cortico-vestibular circuit that bidirectionally mediates MS susceptibility. Whole-brain projectome analysis further revealed anatomically heterogeneous projection subtypes of ACC-medial vestibular neurons. These findings advance our understanding of the cortical mechanisms underlying MS and establish the ACC-MVePC pathway as a mechanistic entry point for future neuromodulatory strategies.

Proteins α-, β-, and γ-synuclein in brain distributed predominantly in presynaptic terminals suggesting their role in regulating neurotransmitter release and signal transduction. Misfolded α-synuclein is involved in the pathology of Parkinson's disease which is characterized by the loss of dopaminergic neurons and the resulting dopamine deficiency. The role of synucleins in the physiology of dopamine-controlled signal transmission is still not fully understood. Using acute brain slices from transgenic mice with α-, β-, γ-synuclein knockout (KO) we studied the effect of synuclein deficiency on dopamine and glutamate-induced calcium signals in neurons and astrocytes. We have found that lack of α- or γ -synuclein decreases the dopamine-induced calcium signal in neurons while γ- or αβγ-KO were characterized by a lower calcium signal in response to glutamate. The ability of dopamine to reduce glutamate-induced calcium signal were altered by γ- and αβγ-synuclein deficiency. Monoamine oxidase-dependent dopamine-induced calcium signal in astrocytes was increased in α-synuclein KO brain slices. αβγ-synuclein deficiency had no effect on mitochondrial Ca[2+]-transport and only γ-synuclein KO led to decrease in the rate of mitochondrial calcium uptake and mitochondrial calcium capacity. Thus, synuclein deficiency alters dopamine- and glutamate -induced calcium signalling in neurons and astrocytes.

Serotonin transporter (SERT), encoded by SLC6A4, is a key regulator of serotonergic neurotransmission and a primary target for selective serotonin reuptake inhibitors (SSRIs). Dysregulation of SERT is implicated in neuropsychiatric and neurodevelopmental disorders, including autism spectrum disorder (ASD). SSRIs, while widely used, have limitations such as adverse effects, drug-drug interactions, and interindividual variability, necessitating safer and mechanistically distinct SERT modulators. This study utilized an integrative in-silico approach to evaluate the SERT inhibitory potential of glabridin, glabrene, and liquiritigenin the phytoestrogens from Glycyrrhiza glabra (licorice), known for neuroprotective properties. Blind and site-specific molecular docking, molecular dynamics simulations, binding free energy calculations, ADMET profiling, and machine learning-based QSAR modeling were employed to characterize ligand-transporter interactions. The compounds glabridin and glabrene exhibited favorable binding affinity for the central S1 substrate-binding site of human SERT, with a comparable or superior binding free energy (-50.35 kcal/mol and -52.41 kcal/mol, respectively) to the reference SSRI paroxetine (-53.04 kcal/mol). The 100 ns MD simulations confirmed stable ligand occupancy and persistent interactions with key residues involved in extracellular gate regulation, stabilizing the SERT outward-open inhibitory conformation. ADMET predictions indicated favorable pharmacokinetic properties, including blood-brain barrier permeability and acceptable toxicity profiles of glabridin and glabrene. QSAR-derived IC50 estimates and combination modeling revealed nonantagonistic, mild positive cooperativity between glabridin and glabrene, supported by dual-ligand docking and MM-GBSA analyses, suggesting complementary orthosteric engagement. These findings position glabridin and glabrene as putative natural SERT modulators, providing a mechanistic basis for their potential use in serotonergic modulation therapeutics, warranting further experimental validation.

Alzheimer's disease is a multifactorial disease characterized by proteinopathy caused by senile plaques and neurofibrillary tangles, leading to neuroinflammation and neuronal damage. Bacopa monnieri, with its extensive usage in the Indian traditional medicinal system, Ayurveda, holds promise in enhancing memory and improving neuronal functions. We performed quantitative phosphoproteomics analysis to understand the temporal dynamics of protein phosphorylation involved in Bacopa monnieri-mediated neuroprotection in the Alzheimer's disease model of IMR-32 cells. The quantitative phosphoproteomics analysis identified 5488 phosphopeptides corresponding to 1427 phosphoproteins. Among the dysregulated peptides in the Aβ42 treatment group, 430 were significantly hyperphosphorylated, and 540 were significantly hypophosphorylated. In contrast, the Bacopa monnieri co-treatment group exhibited 64 significantly hyperphosphorylated peptides and 69 significantly hypophosphorylated peptides. The phosphoproteins altered by Aβ42 were involved in biological functions such as RNA splicing, neuron axonogenesis in the central nervous system, and positive regulation of tau-protein kinase activity. Bacopa monnieri restored key pathways altered by Aβ42, including RNA metabolism, cellular response to stress, signaling by Rho GTPases, and RHOBTB2 GTPase cycle. Kinase mapping of differentially expressed phosphoproteins using the KinMap tool identified CDK11B, CDK12, PRKAA1, PRPF4B, STK10, ROCK1 and ROCK2 as downstream effectors of Bacopa monnieri. The network analysis of restored proteins revealed tight interactions between proteins associated with splicing regulation and stress response. This study offers a comprehensive understanding of phosphoproteome alterations involved in Alzheimer's disease in response to neuroprotection by Bacopa monnieri, which may pave the way for developing therapeutic strategies.

The NKCC1 cotransporter mediates chloride influx into neurons, playing a crucial role in maintaining chloride homeostasis. An increase in NKCC1 raises intracellular chloride concentration, which shifts the polarity of inhibitory synaptic potentials mediated by GABA and glycine towards depolarization. NKCC1 levels are upregulated in certain neurological diseases and psychiatric disorders associated with neuronal hyperactivity. However, the response of NKCC1 in motoneurons following nerve injury, as well as the influence of target-derived neurotrophic factors on this cotransporter, has been scarcely investigated. Here, we have addressed these questions using the oculomotor system as the experimental model. In particular, we evaluated the changes in NKCC1 levels induced by axotomy in extraocular motoneurons, as well as the effects of administering VEGF or BDNF. For this purpose, we performed monocular enucleation of adult rats to induce axotomy of extraocular motoneurons and used immunofluorescence at the confocal microscopy level for image analysis. Our time course study demonstrated that NKCC1 was upregulated in axotomized motoneurons, reaching a maximum at 15 days post-lesion. An interesting finding was that the administration of VEGF prevented this upregulation. BDNF delivery resulted in NKCC1 levels intermediate between control and axotomy. Axotomized motoneurons also showed an increase in soma size that was prevented by administration of VEGF, but not BDNF, consistent with the ability of NKCC1 to transport water into the cell along with ions. The present data suggest that VEGF may have therapeutic potential for neuronal diseases or injuries characterized by increased NKCC1 expression and associated hyperactivity.

The metabolism of neuronal activity is highly localized and cannot be sustained by cell-wide distribution of energy. Neurons and glia organize metabolic enzymes, mitochondria, lipid droplets, and endoplasmic reticulum (ER) contacts into spatially localized microdomains that dynamically couple energy generation to synaptic activity. These metabolic microdomains engage with calcium signaling, redox, and kinase pathways to regulate synaptic plasticity, intrinsic excitability, and homeostatic scaling. Dysregulation of this spatial metabolic control increasingly appears to contribute to neurodevelopmental disorders, epilepsy, and neurodegeneration. Because mitochondrial positioning, dynamics, and ER-mitochondria contacts occupy a central and recurring position among these microdomains, this review focuses in particular on mitochondria-associated metabolic mechanisms while integrating glycolytic, lipid, and astrocytic compartments into a unified framework. We propose that metabolic compartmentalization may constitute an underappreciated modulatory layer influencing circuit function, though the extent and mechanistic specificity of this regulation remain to be fully established. In this review, we discuss current innovations in imaging, metabolomics, and organelle biology to suggest a model whereby metabolic compartmentalization may serve as a modulatory tier of circuit stability and adaptability.

Antenatal depressive symptoms (ADS) are common during pregnancy and are linked to adverse maternal and offspring neurodevelopmental outcomes. The placenta plays a central role in maternal-fetal communication and may function as an epigenetic sensor of maternal psychological stress. However, placental epigenetic signatures associated with ADS remain poorly understood. This study investigated epigenome-wide placental DNA methylation patterns associated with ADS in an Indian cohort. Placental samples were collected at delivery from women recruited in early pregnancy into the STRiDE cohort. Depressive symptoms were assessed at 24-28 weeks' gestation using the Patient Health Questionnaire-9 (PHQ-9). Participants were classified as controls (PHQ-9 ≤ 4; n = 53) or ADS (PHQ-9 > 4; n = 54). Genome-wide DNA methylation profiling was performed using the Illumina Infinium MethylationEPIC array. Epigenome-wide association analysis identified no CpG sites that remained statistically significant after Benjamini-Hochberg FDR correction. Top nominal CpGs showed medium-to-large effect sizes for ADS. Exploratory analyses of the top nominally associated CpGs annotated to genes including TAP2, LRCH1, SLITRK2, RASSF1 and IL3 implicated in immune regulation, cellular signalling and neurodevelopment. Gene enrichment analysis suggested the involvement of biological processes and pathways related to synaptic organization, ion transport, Hippo signalling, and thyroid hormone regulation. In conclusion, the study findings provide preliminary evidence of DNA methylation signatures linked to potential candidate genes and biological pathways that may be relevant to ADS, supporting the need for validation in larger independent cohorts and functional experimental studies.

SH3-domain GRB2-like 3 (SH3GL3), also known as endophilin A3, is highly expressed in the hippocampus; however, comprehensive studies on SH3GL3 expression after ischemia and its protective roles against ischemic damage in the hippocampus are lacking. Here, we examined SH3GL3 expression in the hippocampal CA1 region. SH3GL3 immunoreactivity gradually increased, peaking 12 h after ischemia/reperfusion, and then decreased over time post-ischemia. However, SH3GL3 immunoreactivity increased again in the hippocampal CA1 region 7 days after ischemia and SH3GL3 immunoreactivity in this group was detected in neurons as well as astrocytes. To elucidate SH3GL3's role against oxidative stress and ischemic damage, we synthesized the cell-permeable PEP-1-SH3GL3 fusion protein to facilitate crossing the cell membrane and blood-brain barrier. In an in vitro study, treatment with PEP-1-SH3GL3, unlike its control protein (SH3GL3), was delivered into HT22 hippocampal cells in a concentration- and incubation time-dependent manner. Additionally, PEP-1-SH3GL3 significantly reduced hydrogen peroxide (H2O2)-induced cell death, reactive oxygen species formation, and DNA fragmentation in HT22 cells. In an in vivo ischemia study, treatment with PEP-1-SH3GL3 was delivered into hippocampus and the protein was peaked 3 h after ischemia and protein treatment and thereafter decreased with time after ischemia and protein treatment. Treatment with PEP-1-SH3GL3 significantly reduced traveled distance one day after ischemia and increased the number of surviving cells in the hippocampal CA1 region four days after ischemia in gerbils. PEP-1-SH3GL3 treatment decreased ischemia-induced phagocytic microglia in the stratum pyramidale of the CA1 region four days after ischemia. Furthermore, treatment with PEP-1-SH3GL3 significantly mitigated ischemia-induced oxidative stress (hydroperoxides and malondialdehyde) and pro-inflammatory cytokine release (interleukin-1β, interleukin-6, tumor necrosis factor-α) in the hippocampus 3 and 6 h after ischemia, respectively. These results suggest that PEP-1-SH3GL3 may serve as a therapeutic agent to inhibit neuronal damage caused by cerebral ischemia.

Stroke remains the leading cause of brain injury worldwide, yet current therapeutic strategies primarily focus on restoring cerebral blood flow and do not directly target the brain parenchyma. Ischemic stroke, which accounts for approximately 87% of all cases, induces neuronal damage through depletion of oxygen and metabolic substrates, resulting in acidosis, inflammation, excitotoxicity, and oxidative stress. Carbon monoxide (CO) is an endogenous gasotransmitter generated by heme oxygenase-mediated degradation of heme. Increasing evidence indicates that CO exerts cytoprotective effects by attenuating inflammation and preventing cell death in multiple tissues, including the brain. Previous studies in the mouse middle cerebral artery occlusion (MCAo) model have shown that CO administration prior to ischemia produces histological neuroprotection. The present pilot study introduces two main novelties. First, CO was administered after stroke onset, providing a more clinically relevant therapeutic framework. Second, a multimodal imaging approach was employed to characterize the effects of CO at metabolic, vascular, and anatomical levels. Neuroprotection following MCAo was evaluated using three intraperitoneal injections of the CO-releasing molecule CORM-A1 (3 mg/kg), administered 6, 24, and 48 h after reperfusion. Magnetic resonance imaging was performed at 1 and 7 days post-reperfusion, including T2-weighted and diffusion-weighted sequences, proton spectroscopy ([1]H-MRS), and dynamic contrast-enhanced perfusion imaging. Motor activity was evaluated by Open Field and Vertical Pole assays. Metabolite profiles obtained by [1]H-MRS enabled comparison of metabolic signatures between early and later stages following MCAo. CORM-A1 treatment reduced BBB disruption and decreased the mortality rate at early phase. Thus, metabolite profiles revealed a dissociation between robust BBB protection and lack of metabolic preservation, suggesting that metabolic dysfunction occurs independently of BBB disruption. Overall, this pilot study suggests that CO may promote recovery after ischemic stroke, primarily by preserving BBB integrity and supporting brain metabolic function, but further studies are needed to confirm this effect.

The α-synuclein (aSyn) pathology is a predominant feature of synucleinopathies such as Parkinson's disease (PD). Triggers that may induce aSyn aggregation are not completely understood, but include post-translational modifications. One such modification is aSyn truncation exposing the N-terminal glutamine 79 residue that is subsequently converted into pyroglutamate (pE). The pE79-aSyn variant is prone to oligomerisation and thus highly neurotoxic. Here, we used a Thy1-aSyn PD mouse model overexpressing human wild type aSyn to reveal a possible spatial association of aSyn with matrix metalloproteinase-9 (MMP-9) as aSyn-truncating and with isoglutaminyl cyclase (isoQC) as pE-forming enzymes, respectively. We observed a cellular co-localisation of pE79-aSyn with MMP-9 and isoQC in aSyn overexpressing neurons in the substantia nigra. In addition, MMP-9 and GFAP protein expression increased during aging of Thy1-aSyn mice, whereas that of isoQC was reduced. In order to reveal potential cross-disease mechanisms of pE79-aSyn pathology, its cell type-specific appearance and immunohistochemical co-localisation with MMP-9 and isoQC was also evaluated in the tg2576 Alzheimer's disease (AD) mouse model. Here, a different cellular expression pattern with substantial co-localisation of pE79-aSyn with MMP-9, isoQC, QC and aSyn predominantly in amyloid plaque-surrounding astrocytes was detected. Together, these data indicate that the same enzymatic activities, MMP-9 and isoQC, might be involved in the subsequent pE79-aSyn generation in PD and AD mouse models. The cellular origins, however, differ between the mouse models with neuronal expression of aSyn and its modifying enzymes in the PD mouse model and astrocytic expression in the AD mouse model.