Chronic sleep deprivation (SD) disrupts central nervous system homeostasis, promoting behavioral alterations and glial remodeling within limbic structures. Although simvastatin exhibits pleiotropic effects, its influence on astrocytic and microglial responses during prolonged sleep loss remains poorly understood. This study investigated the effects of SD and simvastatin on behavior, systemic inflammatory mediators, and glial reactivity in the dorsal hippocampus (HPC) and amygdala (AMY). Sixty male Wistar rats (~75 days old; n = 15/group) were assigned to Control (CG), Sleep Deprived (SD), Simvastatin 4.2 mg/kg (SIM4.2), or Simvastatin 20 mg/kg (SIM20) groups. Animals underwent the modified multiple platform method (18 h/day) for 45 consecutive days, with daily oral simvastatin administration. Social behavior was assessed using the resident-intruder test, circulating cytokines by ELISA, and glial responses by GFAP and IBA-1 immunohistochemistry, including microglial morphological classification (Types I-III). SD increased aggressive/reactive behavior and astrocytic and microglial reactivity in the dorsal HPC, accompanied by a shift from homeostatic (Type I) toward reactive (Types II and III) microglial phenotypes. Simvastatin attenuated these glial alterations, restoring a more homeostatic microglial profile and increasing non-social exploratory behavior. In contrast, glial alterations in the AMY were comparatively limited, indicating region-specific susceptibility to SD. Peripheral cytokine analysis revealed selective immunomodulatory effects, including reduced TGF-β and increased IL-8 in SIM20, whereas TNF-α and IL-6 remained unchanged. Overall, simvastatin modulated behavioral, systemic inflammatory, and glial responses to SD, supporting its pleiotropic effects and highlighting region-specific glial remodeling as a potential target for mitigating the consequences of chronic sleep loss.

Microglial polarization critically influences neuroinflammation and recovery after ischemic stroke. The role of C-type lectin domain family 7 member A (CLEC7A), a potential regulator in this process, remains unclear. Integrated bioinformatics analysis of Gene Expression Omnibus datasets identified CLEC7A as a hub gene. Its functional role was investigated using in vitro oxygen-glucose deprivation (OGD) models in BV2 microglia/HT22 neuron co-cultures and in vivo rat middle cerebral artery occlusion (MCAO) models. CLEC7A was knocked down in vitro and in vivo. Functional outcomes were assessed via infarct volume and neurobehavioral scores. Levels of inflammation factors were evaluated by enzyme-linked immunosorbent assay, and microglial polarization markers were assessed by western blot, immunohistochemistry, and immunofluorescence. Recombinant Chemokine (C-X-C motif) ligand 1 (CXCL1) agonist was employed for rescue experiments. Herein, CLEC7A knockdown reduced MCAO-induced infarct size, attenuated brain injury, and neurological deficits in vivo, and improved cell viability and reduced apoptosis in vitro. Furthermore, CLEC7A knockdown suppressed pro-inflammatory microglial phenotypic markers while enhancing anti-inflammatory markers in vivo and in vitro. This protective effect was mediated through the Cytokine-cytokine receptor interaction pathway, specifically via downregulation of CXCL1/C-X-C motif chemokine receptor 2 (CXCR2), as the benefits were reversed by recombinant CXCL1 treatment. In summary, silencing CLEC7A alleviates ischemic brain injury by promoting an anti-inflammatory microglial phenotype. Targeting CLEC7A to inhibit the CXCL1/CXCR2 axis represents a promising therapeutic strategy for mitigating neuroinflammation and improving recovery after stroke.

Adolescent binge alcohol alters late-developing brain regions and increases the risk for long-term reward, cognitive, and emotional dysregulation. Adolescent intermittent ethanol (AIE) exposure in rodents produces similar behavioral alterations into adulthood, but the effects of acute high-dose ethanol on patterns of neuronal activation in late developing brain regions remain poorly understood. In the current study, adolescent male and female cFos-LacZ rats were acutely challenged with water or 4 g/kg ethanol intragastrically (IG) on postnatal day (P) 25 or P45, early- and late-adolescence, with brains collected 1 h later. P45 rats with a history of water or AIE (10 exposures every other day from P25 to P45) were included as a chronic exposure condition. β-galactosidase expression was used as a proxy for Fos neuronal activation. Acute IG gavage increased neuronal activation in multiple brain regions irrespective of water or ethanol challenge, and increases were attenuated by adolescent chronic exposure. Increased neuronal activation was evident only in the central amygdala (CeA) after acute ethanol challenge, with this effect being attenuated by AIE. Functional network mapping revealed age-, sex-, and exposure-related differences: water-exposed adolescent males had salient network hub regions, while control females had age-related transitions from salient to executive control network regions. Ethanol disrupted these trajectories. In males, acute ethanol reduced functional network connectivity, with chronic ethanol decentralizing hubs. In females, ethanol enhanced connectivity centered on the nucleus accumbens. These findings highlight the CeA as an ethanol-sensitive region across sexes, but reveal sex differences in adolescent ethanol exposure on functional networks.

Heat shock protein 72 (Hsp72), a stress-inducible member of the Hsp70 family, has been implicated in mitigating the pathogenic effects of amyloid-beta (Aβ) and tau pathology; both key factors associated with the development and progression of Alzheimer's disease (AD). However, no in vivo study has been conducted to investigate the ability of Hsp72 to provide benefit when both Aβ and tau pathology are present concurrently. This study set out to utilize a genetic approach (transgenic overexpression) and a pharmacological validation approach (BGP-15) to increase Hsp72 expression in mice exhibiting Aβ and tau pathology (5xFADxTg30 model). Our findings indicate that genetic Hsp72 overexpression did not significantly alter Aβ or tau burden, deficits in motor performance, or alterations to body composition in this model, but modestly improved survival rates (driven by findings in male mice) and altered anxiety-like behavior (driven by findings in female mice). Similarly, BGP-15 treatment was unable to rescue behavioral traits, motor deficits, body composition, or alleviate Aβ or tau accumulation, although this treatment also showed a trend towards enhancing survival (again in male mice) and altered anxiety-like behavior (specifically in female mice). While the 5xFADxTg30 mice demonstrated seizure susceptibility compared to WT mice, BGP-15 was unable to alleviate this trait. These findings were independent of any measurable increase in Hsp72 abundance in the brain in response to BGP-15. Together, these findings suggest a limited impact of genetic overexpression and pharmacological targeting of Hsp72 protein abundance in this combined Aβ and tau model, although some sex-specific differences are noted.

Complex neurodevelopmental disorders such as autism spectrum disorders (ASD) and schizophrenia are characterized by impaired social interactions, cognitive deficits, and repetitive behaviors. Genome-wide association studies (GWAS) have identified the α5 nicotinic acetylcholine receptor (α5-nAChR) subunit as a significant risk factor for these neuropsychiatric conditions. The α5 subunit is a critical modulator of neural circuit dynamics, specifically through its functional involvement within vasoactive intestinal peptide (VIP)-positive interneurons; however, its role in the sex-dependent maturation of behavioral phenotypes remains poorly understood. We characterized α5-nAChR knockout (ACNA5) mice to investigate the neurodevelopmental consequences of α5 subunit loss. ACNA5 mice displayed sexually dimorphic and age-dependent core symptoms relevant to ASD and schizophrenia. Regarding anxiety-like behavior, there was an opposite sex pattern between genotypes, evident only in adulthood. Cognitive assessment using the novel object location task revealed early-onset spatial memory deficits in ACNA5 females, whereas males exhibited a progressive decline from adolescence to adulthood. In the social domain, adult ACNA5 mice failed to exhibit social novelty preference; females displayed complete social indifference, while males displayed a pronounced familiarity bias. In addition, ACNA5 mice of both sexes displayed amplified repetitive behavior, emerging earlier in males, and poor nest-building scores across developmental stages. Together, these findings identify the α5-nAChR subunit as a crucial modulator of the maturation of neural circuits underlying social motivation, cognition, and emotional regulation. Our results implicate α5-containing nicotinic receptors in the pathogenesis of neurodevelopmental disorders and establish the ACNA5 mouse as a valuable model for investigating sex-specific developmental trajectories and therapeutic windows.

Spinal cord injuries (SCI) are a major health concern, resulting in substantial functional deficits, including motor and sensory impairments around and below the affected area. Despite continuous efforts, current spinal cord repair strategies have shown limited therapeutic success. The adipose-derived stromal vascular fraction (SVF) is a heterogeneous cell population with trophic, angiogenic, and immunomodulatory properties that has previously been shown to improve functional recovery after experimental SCI. The present study investigated whether treadmill rehabilitation could enhance the therapeutic effects of autologous SVF transplantation following severe thoracic SCI. Thirty-six male Sprague Dawley rats were divided into four groups: NaCl (sodium chloride) (spinal cord contusion with NaCl injection), SVF (contusion with SVF autograft), NaCl-T (contusion with NaCl injection and treadmill training), and SVF-T (contusion with SVF autograft and treadmill training). Behavioral recovery was assessed weekly over 12 weeks using the BBB locomotor score and ladder climbing test, while gait and electrophysiological analyses were performed at the study endpoint. The combined treatment produced greater improvements in locomotor performance than either SVF transplantation or treadmill training alone, as demonstrated by higher BBB and ladder climbing scores together with improved gait parameters. Electrophysiological analyses further showed that SVF treatment restored rate-dependent depression of the H-reflex, reflecting improved spinal sensorimotor inhibitory function. Collectively, these findings demonstrate that treadmill rehabilitation potentiates the functional benefits of autologous SVF transplantation and supports the combination of cell therapy and rehabilitation as a promising strategy to enhance functional recovery after traumatic SCI.

In humans, chronic pain is characterized by a combination of heightened nociceptive sensitivity along with emotional comorbidities, with more women impacted than men. A reported limitation of preclinical models is that they often fail to encapsulate this complexity, and few studies have directly compared behavioral outcomes between male and female mice. The intraplantar Complete Freund's adjuvant (CFA) inflammatory pain model is a widely used preclinical model of persistent mechanical and thermal hypersensitivity, which triggers sex-dependent adaptations in neuronal signaling. However, the literature regarding the duration of pain hypersensitivity and the presence or absence of associated locomotor and anxiety-like changes is inconsistent. Therefore, this study aimed to systematically assess the CFA model's capacity to duplicate pain comorbidities in male and female mice. CFA-injected or saline control male and female mice were assessed over 3 weeks for mechanical and cold nociceptive sensitivity (von Frey and acetone test), locomotion (open field test), and anxiety-like behaviors (light-dark and elevated plus maze tests). CFA-injected mice of both sexes reliably developed mechanical hypersensitivity and cold allodynia. Transient locomotor deficits were observed only in male mice at early timepoints, and no changes in anxiety-like behaviors in either males or females were observed. Hence, the CFA persistent pain model is a practical tool for inducing pronociceptive states in male and female mice but does not reliably produce anxiety-like comorbidities over the tested time periods, suggesting that additional factors may be necessary to elicit these behavioral outcomes.

The majority of animal models of Parkinson's disease (PD) focus on motor symptoms that are induced by unilateral injections of such neurotoxins as 6-hydroxydopamine (6-OHDA) in nigrostriatal dopaminergic pathways. However, motor changes that are induced by unilateral 6-OHDA injections may interfere with the identification of cognitive and affective dysfunctions induced by dopaminergic neurodegeneration. To select an appropriate method for studying nonmotor symptoms of PD and potential neuroprotective treatments, the present study compared behavioral effects of bilateral 6-OHDA infusions directly in the substantia nigra pars compacta (SNpc) or striatum in rats. A battery of behavioral tests, including affective and cognitive tasks, was performed for 22 days after 6-OHDA nigrostriatal lesions. The massive degeneration of tyrosine hydroxylase-immunoreactive neurons was observed in the SNpc, striatum, and ventral tegmental area with 6-OHDA infusions in either the SNpc or striatum. Concerning functional outcomes, 6-OHDA infusions in the striatum decreased general exploratory activity 7 days after the lesion. Rats that received 6-OHDA in the SNpc exhibited cognitive impairments and despair-like behavior. A decrease in the number of newborn neurons was found in the hippocampus in rats that received 6-OHDA in the striatum, indicating a alteration of neuron maturation. 6-OHDA infusions in both the SNpc and striatum impacted the maturation of newborn hippocampal neurons. These results indicate that bilateral injections of 6-OHDA in the SNpc might be useful for studying nonmotor symptoms of PD.

Oligodendrocytes (OLs) are essential for central nervous system (CNS) function through their role in axon myelination, and their dysfunction is implicated in a range of neurological disorders. Despite this, in vitro modeling of human OL biology remains limited by the scarcity of primary human OLs. Furthermore, while induced pluripotent stem cells (iPSCs) offer a promising source of human OLs, current differentiation protocols remain complex, inefficient, and time-consuming. Here, we present an optimized protocol to generate OLs from iPSCs (iOLs) using defined soluble factors supplemented in the culture media. Within 28 days, cultures yielded an average of 85% O4+ iOLs, and by Day 38, approximately 70% expressed MBP, a key marker of mature OLs. Bulk RNA-seq analysis confirmed a stepwise transcriptional progression consistent with OL lineage identity, with upregulation of key OL-specific transcripts and gene expression profiles. Comparative transcriptomic analyses further revealed increased expression of gene networks associated with myelination, extracellular matrix remodeling, and gliogenesis when iOLs were cultured on aligned nanofiber scaffolds. Importantly, iOLs formed compact myelin sheaths around axons and showed enhanced maturation in a three-dimensional (3D) environment, highlighting the importance of spatial and matrix-derived cues in OL development. This study establishes a cost- and time-efficient approach for generating functional OLs from iPSCs, with broad applicability for disease modeling, drug screening, and the development of regenerative therapies.

This narrative review examines the essential roles of heparan sulfate proteoglycans (HSPGs) in brain development, synaptic function, axonal guidance, synapse formation and stabilization, and the establishment of correctly interconnected neural networks. Distinct HSPG profiles help shape precise neural circuits, whereas HSPG dysregulation is associated with impaired neurodevelopmental processes, cognitive decline, and pathological changes in brain tissues. These findings emphasize the importance of HSPGs in normal brain function and in disease-associated tissue dysfunction. HSPGs are a diverse group of proteins with critical roles in the CNS and PNS, including synaptic function, neurodevelopment, neurodegeneration, cell migration, and regulation of neuroprogenitor stem cell niches in the subventricular ependymal zone and subgranular dentate gyrus. Together, the diverse functions of HSPGs place them as master regulators of tissue form and function in health and disease.

Mild traumatic brain injury (mTBI) is associated with persistent physical, cognitive, and emotional symptoms, yet the functional brain changes that accompany recovery remain incompletely understood. This longitudinal study investigated brain entropy (BEN), a resting-state measure of irregularity or complexity of spontaneous BOLD activity derived from resting-state functional magnetic resonance imaging (rs-fMRI), during the first year following mTBI. Data of rs-fMRI were acquired from 48 patients with mTBI at the acute (< 14 days), 6-month, and 12-month post-injury visits, and 34 healthy controls (HCs). BEN was quantified using sample entropy. Patients with mTBI also underwent behavioral assessments evaluating quality of life and cognitive function. Behavioral assessments demonstrated progressive improvements in patient-reported quality of life and objective cognitive performance. Cross-sectional analyses revealed dynamic, time-dependent alterations in BEN. Compared with HCs, patients with mTBI exhibited higher BEN in precuneus, temporal, occipital, and sensorimotor regions during the acute and 6-month stages, whereas lower BEN was observed in sensorimotor, occipital, and frontoparietal regions at the 12-month follow-up. Longitudinal analyses demonstrated progressive regional reductions in BEN over time. Several associations between longitudinal changes in regional BEN and cognitive performance were nominally significant, particularly in the precuneus, but none survived multiple comparison corrections. These findings indicate that mTBI recovery is accompanied by dynamic, regionally specific changes in resting state BOLD irregularity. BEN may therefore provide a promising imaging biomarker for tracking the evolving neural dynamics underlying recovery following mTBI.

Chronic pain in later life may be accompanied by alterations in brain structure and cognition, but whether pain extent and central sensitization symptoms identify distinct brain-behavior patterns remains unclear. We examined associations of pain extent and central sensitization symptoms, assessed using the 9-item Central Sensitization Inventory (CSI-9), with regional gray matter volume and cognitive function in community-dwelling older adults. This cross-sectional study included 272 participants with chronic pain from the Bunkyo Health Study. Participants were classified as having single-site or multisite pain and by CSI-9 score as having lower or higher scores, with ≥ 12 defining the higher group. Regional gray matter volume was quantified using 0.3-Tesla magnetic resonance imaging, and cognition was assessed using the Trail Making Test Part B (TMT-B), processing speed, and global and domain-specific measures. Pain extent and CSI-9 group interacted for TMT-B performance, with the longest completion time in participants with single-site pain and a higher CSI-9 score. No other cognitive outcome remained significant after correction for multiple testing. In categorical analyses, the higher CSI-9 group had smaller volumes in the right middle frontal gyrus, bilateral anterior cingulate cortex, right insula, right hippocampus, and bilateral amygdala, whereas pain extent and the interaction were not associated with regional volume. In a contextual comparison, only the single-site/higher CSI-9 group showed slower TMT-B performance than participants with no current pain. Pain extent and central sensitization symptoms may represent partly distinct dimensions of chronic pain, although the small single-site/higher CSI-9 group and attenuation in several sensitivity analyses warrant caution.

The Endoterpenoid System (ETS) is a proposed new membrane-based framework that ensembles classical endocannabinoid signaling (ECS) with ectopically expressed olfactory GPCRs, ion channels, and microbially derived terpenoids. Integrated with this model is the proposed endoterpenoidome (eTBome) machine: a chemically diverse pool of endogenous cannabinoids, dietary terpenoids, and microbial metabolites whose lipophilicity drives partitioning into cholesterol-rich lipid rafts. Within these nanoscale microdomains, ETS components undergo co-localization and co-expression, enabling receptor heteromerization and β-arrestin-scaffolded signalosomes that facilitate dynamic crosstalk and emergent responses such as bistable apoptotic switches and context specific modulation of Gᵢ/o, Gₛ/olf, and Gq pathways. We detail molecular mechanisms underpinning ETS behavior, including lipid mediated allostery, scaffold protein recruitment, and lateral diffusion effects, and highlight the gut microbiota as pivotal architects of the eTBome through terpene synthase-driven production of bioactive ligands. Germ free and antibiotic treated animal models underscore the dependence of ETS ligand pools and receptor distributions on microbial colonization. This article proposes key avenues for experimental validation, including high resolution structural studies of CB-OR heteromers, quantitative lipidomic mapping of eTBome distributions, live cell super resolution imaging of receptor nanoclusters, and gnotobiotic manipulations of microbial terpene synthesis. By introducing them as proposals to the scientific community and by integrating ECS/eCBome biology with olfactory receptor (OR) and microbial metabolite research, the ETS/eTBome concept offers a cohesive hypothesis for lipid-driven GPCR crosstalk and indicated non-standard targets for therapeutic modulation in cancer, neuroinflammation, and metabolic disorders.

To obtain rewards, animals must select actions while facing threats, often under competing appetitive and defensive drives and with uncertainty about harm. While neural circuits controlling isolated threats or rewards are well characterized, it remains unclear which specific cortical and subcortical nodes are causally necessary to organize behavior during motivational conflict. Here, we used the step-down avoidance-mediated conflict (SDAmC) task in adult male rats, which quantifies avoidance, risk assessment, and reward approach within the same session. We performed pharmacological inactivation across eight candidate structures implicated in valence and action selection: prelimbic (PL) and infralimbic (IL) cortices, lateral orbitofrontal cortex (lOFC), anterior (aIC) and posterior (pIC) insular cortices, lateral habenula (LHb), basolateral amygdala (BLA), and nucleus accumbens (NAc). Inactivation revealed a precise anatomical dissociation within this network. Silencing PL or pIC facilitated approach behavior during conflict, but with dissociable effects on risk assessment. In contrast, BLA inactivation induced a broader behavioral disinhibition evident even in non-conflict conditions, whereas NAc inactivation disrupted the temporal organization of approach, yielding a fragmented behavioral phenotype. Notably, inactivation of IL, lOFC, aIC, and LHb did not alter conflict resolution in this paradigm. Together, these findings identify a selective cortico-limbic network in which PL and pIC are necessary for limiting approach under conflict, BLA contributes to avoidance expression across motivational states, and NAc contributes to approach-related behavioral organization under conflict, constraining the set of brain regions that are necessary to organize behavior when reward seeking competes with threat.

Epilepsy is one of the most common neurological disorders worldwide, affecting around 1% of the population. The epilepsies represent a diverse group of conditions, ranging from acquired forms resulting from neurological insults to common multifactorial epilepsies and rare, often monogenic epilepsies caused by highly penetrant genetic variants. The genetic epilepsies demonstrate frequent comorbidity with a range of neurodevelopmental and psychiatric disorders, and epileptic seizures are also a common feature of neurodevelopmental disorders such as Fragile X syndrome and Rett syndrome. Astrocytes, the most numerous glial cells in the central nervous system, have emerged as crucial players in the pathophysiology of acquired epilepsies. Whilst the contribution of astrocytes to acquired epilepsy has been widely reviewed, astrocyte dysfunction in rare genetic epilepsies or neurodevelopmental disorders has been neglected, despite the fact that the genes implicated are expressed in astrocytes, albeit to a lesser extent than in neurons. Additionally, affected individuals with rare genetic epilepsies are more likely to exhibit drug-resistant seizures, highlighting the need to identify novel therapeutic targets. In this paper, we review the existing literature on astrocyte dysfunction in genetic epilepsy syndromes and neurodevelopmental disorders with seizures. We have identified several key studies that highlight alterations in crucial astrocyte functions including calcium signaling and ion homeostasis. Our review highlights the need for further research to establish the contribution of astrocyte dysfunction to neuronal health and seizure activity in rare genetic epilepsies.