Neurochemistry International
○ Elsevier BV
Preprints posted in the last 90 days, ranked by how well they match Neurochemistry International's content profile, based on 10 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Kilanko, F. J.; Adele, B. O.
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Abstract Objectives To evaluate and compare the neuro-behavioural safety profiles of piroxicam and nitroglycerine by investigating their differential effects on cognitive function, spatial and recognition memory, and hippocampal neurochemistry in a di-oestrous female Wistar rat model. Methods Female Wistar rats at di-oestrous were randomly assigned to receive distilled water, piroxicam, or nitroglycerine orally for four consecutive days. Following treatment, spatial and recognition memory were evaluated using standard behavioural paradigms. Hippocampal tissues were analysed for acetylcholinesterase and glutamate activity, oxidative stress markers, and neuroinflammatory indices. Results Piroxicam improved recognition memory and was associated with increased glutamatergic activity and a compensatory rise in superoxide dismutase. However, it also elicited elevated nitric oxide signaling, lipid peroxidation, and localized neuroinflammatory markers in the hippocampus. In contrast, nitroglycerine impaired non-spatial memory during di-oestrous. Although both treatments preserved working memory, they produced distinct effects on object recognition, memory discrimination, oxidative stress parameters, and neuroinflammatory mediators. Conclusions Piroxicam and nitroglycerine exert differential effects on cognition and hippocampal neurochemistry during di-oestrous. Piroxicam improved recognition memory and produced distinct hippocampal neurochemical alterations, whereas nitroglycerine impaired recognition memory. These findings highlight the influence of menstrual pain therapeutics on cognitive function and hippocampal physiology under hormonally sensitive conditions. Keywords: cognitive function; cognitive impairment; cyclooxygenase inhibitors; neuroinflammation; neurochemistry
Kim, Y.-J.; Woo, D. H.
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Mancozeb, a widely used fungicide composed of manganese ethylene-bis-dithiocarbamate with zinc salts, has raised concerns due to its potential neurotoxic effects. In this study, we investigated how chronic oral administration of mancozeb affects astrocyte function and neurobehavior in mice, focusing on store-operated Ca{superscript 2} entry (SOCE), mediated by Orai1 and STIM1. Mancozeb treatment at 0.5 {micro}g/kg/day for 4 weeks reduced glial fibrillary acidic protein (GFAP) expression in the hippocampus and corpus callosum of mice, indicating astrocyte atrophy. Further, administration at the human acceptable daily intake (30 {micro}g/kg/day) for 1 week induced hippocampal astrocyte atrophy and hyperlocomotor activity in open field tests. In vitro experiments revealed that mancozeb specifically inhibited SOCE in astrocytes by targeting the Orai1/STIM1 complex, as its inhibitory effect was abolished by short hairpin RNA (shRNA)-mediated knockdown of Orai1 or STIM1, but not by knockdown of TRPA1 or scramble shRNA. This demonstrates that mancozeb-mediated SOCE inhibition critically depends on the presence of Orai1 and STIM1, highlighting the molecular specificity of its action. Furthermore, mancozeb diminished endoplasmic reticulum (ER) Ca{superscript 2} stores and P2Y1 receptor agonist-induced Ca{superscript 2} transients. Electrophysiological analyses revealed that mancozeb selectively decreased the inhibitory postsynaptic current frequency without affecting excitatory currents, suggesting reduced astrocyte-mediated GABA release. Collectively, these findings demonstrate that mancozeb disrupts astrocytic Ca{superscript 2} homeostasis through Orai1/STIM1-dependent SOCE inhibition, leading to astrocyte atrophy and altered inhibitory neurotransmission, which may underlie the observed behavioral changes. These results highlight the potential neurotoxic risk posed by mancozeb via the impairment of astrocyte function and intracellular Ca{superscript 2} regulation. Importantly, these neurotoxic effects occurred at concentrations below current regulatory safety limits (ADI), indicating that mancozeb-induced disruption of astrocytic Ca{superscript 2} signaling provides a mechanistic basis for re-evaluating established human safety exposure standards. Environmental ImplicationsOur findings highlight that the widespread use of mancozeb has a significant impact on brain health. Mancozeb was shown to induce astrocyte atrophy even at low concentrations, amounting to six times the human acceptable daily intake. Mancozeb causes impairment of GABAergic synaptic transmission of neurons by disrupting the Ca{superscript 2} homeostasis via inhibition of Orai1 and STIM1 of astrocytes. These findings indicate that current regulatory standards significantly underestimate the risks of long-term mancozeb exposure to brain health. Therefore, this study underscores the risks of astrocyte-mediated neurotoxicity resulting from pesticide residue ingestion and emphasizes the need to rigorously re-evaluate current exposure limits from the perspective of brain health.
Peshattiwar, V. v.; Swain, C.; Pokharel, D.; Le, K.; Kennedy, I.; Venkiteswaran, K.; Subramanian, T.
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The recent growing evidence support the existence of two subtypes of Parkinsons disease (PD), a body first and brain first subtype owing to variability in the disease site of onset as well as disease progression. Animal models which could replicate the specific differences of these subtypes are important to explore the pathophysiology as well as to evaluate novel treatment options. Here, we describe an animal model of body first PD subtype developed using repeated low dose exposure of environmental neurotoxin Paraquat (P) and Lectin (L) to characterize its PD-like manifestations. We administered P+L (P+L, p.o.) daily to rats for 90 days. These animals underwent motor and non-motor behavioral tests at various time intervals. After 21 weeks, post-mortem histopathological analysis was performed to assess neurodegeneration. Onset of motor deficits initiated unilaterally from week 4 of P+L followed by gradual progression towards bilateral symptoms that were levodopa responsive. This model also replicates non motor features including cognitive deficits in tests like Novel Object Recognition Test and Y maze as well as sleep abnormalities. The histopathology showed nigrostriatal dopaminergic degeneration and proteinase K resistant S129 alpha-synucleinopathy both in the gut and the brain. The replication of both progressive motor and non-motor features in this rat model corroborates body first subtype of PD therefore making it an attractive option for testing neuroprotective experimental therapeutics and avenue to understand pathophysiological mechanisms.
Hasan, A. K. M. M.; Rachamalla, M.; Nigoyi, S.; Chivers, D. P.
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Bisphenol S (BPS), a widely used substitute for bisphenol A, is increasingly detected in aquatic environments; however, its neurodevelopmental effects remain insufficiently understood. This study investigated whether developmental exposure to an environmentally relevant concentration of BPS disrupts social behaviour and underlying neurobiological pathways in zebrafish (Danio rerio). At 21 days post-fertilization, BPS-exposed larvae exhibited a significant reduction in social preference, indicating impaired conspecific interactions. Neurochemical analysis revealed a marked increase in serotonin (5-HT) levels, whereas lipid peroxidation (MDA) remained unchanged, suggesting the absence of overt oxidative damage. Gene expression profiling demonstrated a dysregulated antioxidant response, suppression of apoptotic signaling, and pronounced upregulation of serotonergic receptors and transporters. To resolve system-level mechanisms, protein-protein interaction (PPI) network analysis identified BDNF and CREB1 as dominant regulatory hubs, with the serotonergic synapse pathway as the most significantly enriched term. Molecular docking further demonstrated direct binding of BPS to multiple serotonergic targets, including HTR1A and TPH2, supporting receptor-level interference. Expanded network and pathway analyses revealed coordinated enrichment of monoamine GPCR, oxidative stress, and inflammatory pathways. These findings demonstrate that BPS induces serotonergic dysregulation and network-level reprogramming rather than significant oxidative damage, leading to behavioural impairment. This study provides a multi-scale mechanistic framework linking molecular perturbations to neurobehavioural outcomes, identifying serotonergic signaling and BDNF-CREB1 pathways as central targets of BPS neurotoxicity.
Komal, P.
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Vitamin D3 (VD) deficiency is a global health concern, and its supplementation has been shown to alleviate inflammation and oxidative stress across numerous neurological disorders. However, the beneficial effect of this common nutraceutical in schizophrenia (SCZ) remains inadequately explored. The present study investigated the presupplementation effects of VD on positive and cognitive symptoms in a MK-801induced mouse model of SCZ. MK-801, a non-competitive NMDA receptor antagonist, is a widely used drug that mimics some of the psychotic symptoms associated with SCZ. The repeated administration of a single dose of MK-801 (0.5mg/kg; intraperitoneally) for two weeks produced hyperlocomotion, anxiety- like behavior, and working memory deficits in MK-801-induced SCZ-like mice. These behavioral abnormalities were significantly attenuated in VS5 mice (SCZ mice presupplemented with 500 IU/kg/day of VD). At the molecular level, VD rescued gene expression of major NMDA receptor subunits (NR1, NR2A, NR2B), 7 nicotinic acetylcholine receptors (7nAChRs), and neurotrophin factors (NGF and BDNF). A restoration of PSD-95 protein expression, accompanied by downregulation of calcineurin, was also observed in the prefrontal cortex (PFC) of VS5 mice, suggesting protective effects of VD on synaptic communication and function in SCZ. In vitro studies showed that calcitriol (1 M) treatment of HEK-293 T cells transfected with 7nAChRs potentiated the single-channel current amplitude and demonstrated a direct modulatory effect of this nutraceutical on 7nAChRs expression and function. In silico JASPAR analysis further identified putative Vitamin D response elements (VDREs) within the promoter regions of various target genes, supporting the genomic action of VD. Additionally, VD deficiency was observed in Indian SCZ patients, highlighting its potential clinical relevance. Together with our previous findings (Manjari et al., 2022, 2023), the present study also demonstrates anti-inflammatory, anti-cholinesterase, neurotrophic, and synaptic-enhancing effects of VD, deepening our understanding of the multifaceted neuroprotective effects of the "D3" neurosteroid in neuropsychiatric disorders such as SCZ. HighlightsO_LIVD presupplementation improves the behavioral deficits in MK-801 induced SCZ mice. C_LIO_LINutraceutical intervention normalizes the gene expression of major NMDARs subunits namely, NR1, NR2A, NR2B, in the PFC of SCZ mice. C_LIO_LIVD mediates a restoration in the expression and function of 7nAChRs in SCZ mice. C_LIO_LIVD exhibits neuroprotective, neurotrophic, synaptoprotective, anti-inflammatory and anti-acetylcholinesterase effects, highlighting its therapeutic potential in SCZ. C_LI
Jung, O.; Hoffmeister-Ullerich, S.; Omriouate, A.; Plumhoff, J.; Kreutz, M. R.; Grochowska, K. M.; Morellini, F.
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Huntingtons disease (HD) is a progressive neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin (HTT) gene. The disease is characterized by movement disorders, and it also presents with personality changes, including apathy and aggression, along with cognitive decline. While most animal models for HD have been validated for motor deficits, less is known about alterations in other behavioral functions. Here, we performed a longitudinal study to analyze the behavior of a knock-in mouse model of HD with a chimeric mouse/human exon 1 containing 140 CAG repeats inserted in the murine huntingtin gene. We specifically inquired about the onset of cognitive impairments in knock-in mice and whether changes in various behavioral functions such as locomotion, anxiety, and cognition correlate at the individual level. Our data indicate that female and male knock-in mice exhibit reductions in body weight, novelty-induced locomotion, and remote spatial memory retrieval. However, social behavior, working, and short-term memory remain unaffected. Within knock-in mice, lower open-field activity correlated with poorer remote memory performance. Moreover, CAG repeat length negatively correlated with locomotor activity and spatial memory, indicating that greater repeat expansion predicts more severe behavioral impairment. These findings identify early affective changes, followed by selective long-term memory and locomotor deficits, in knock-in mice, supporting this model as a useful platform for studying prodromal HD and repeat-length-dependent disease variability. HighlightsO_LICAG140 knock-in mice show early anxiety, later reduced locomotion and memory deficits C_LIO_LILong-term and remote memory are impaired while short-term and working memory are spared C_LIO_LILower locomotion at the age of 8 months correlates with poorer memory at 14 months of age in individual CAG140 knock-in mice C_LIO_LIGreater CAG repeat length predicts worse locomotion and memory C_LI
Catrupay-Valdebenito, C.; Burgos, C. F.; Salgado-Martinez, B.; Vejar, C.; Fuentes, N. A.; Yevenes, G. E.; Moraga-Cid, G.; Castro, P. A.
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BackgroundNeurulation is a fundamental process in the formation of the central nervous system (CNS). The process begins with the folding and fusion of the neural plate to form the neural tube which subsequently gives rise to the development of the brain and spinal cord. Environmental and genetic factors that disrupt neurulation can induce neural tube defects (NTDs) and consequently cause additional developmental complications, including motor impairments. Purinergic signaling is a conserved form of extracellular communication (i.e. paracrine, synaptic signaling) that plays a role in early development. This signaling is mediated by purine nucleotides and nucleosides, which activate metabotropic P2Y and ionotropic P2X purinoceptors, respectively. Distinct patterns of intracellular calcium dynamics are observed throughout vertebrate development, from fertilization through organogenesis, including neurulation. Among P2X receptors, P2X4 is an ATP-modulated, Ca2+-permeable, ligand-gated ion channel characterized by having the highest Ca2+ permeability and is known to be modulated by ivermectin (IVM). ObjectiveOur investigation focuses on assessing the effects of IVM treatment during neurulation and evaluating the impact of this drug on phenotype, motor behavior and neuromuscular junction (NMJ) structure at tadpole stage. These results were compared with those obtained following separate treatments with compounds that specifically block glycine, GABA(A) and nACh receptors, all which have been described as IVM targets. ResultsIn this study we demonstrate the transcriptional expression for both P2X and P2Y purinergic receptors during neurulation, as well as the expression of P2X4. Following IVM neurula-treatments, we observed neural tube defects (NTDs), pigmentation changes, motor paralysis and alterations in neuromuscular junction (NMJ) structure, particularly affecting axonal branching. In contrast, treatment with the blockers strychnine, bicuculline and -bungarotoxin, used to assess the involvement of GlyR, GABA(A)R and 7nAChR, respectively, failed to show similar outcomes. ConclusionsIn summary, our results highlight the critical role of purinergic signaling during early development, particularly P2X4 receptor mediated signaling during neurulation which may account for the pharmacological effects induced by the positive allosteric modulator ivermectin.
Tanaka, G.; Nakamura, S.; Goto, R.; Kubota, A.; Sakamoto, N.; Awazu, A.
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ObjectiveIn recent years, the number of cats kept as companion animals has increased, leading to a growing demand for veterinary care. Although some histone deacetylase (HDAC) inhibitors are promising for the treatment of human cancers and neurological diseases, comprehensive systematic research on HDAC inhibitors in domestic cats remains insufficient. Therefore, this study aimed to investigate the effects of HDAC inhibitors on the transcriptome of feline cells. MethodsTwo types of cells derived from domestic cats, Crandell-Rees Feline Kidney (CRFK; kidney-derived) cells and PG-4 cells (astrocyte-derived), were treated with four HDAC inhibitors (panobinostat, trichostatin A, valproic acid, and vorinostat) for 24 h. Transcriptomic changes after treatment were examined using RNA sequencing. ResultsHDAC inhibitor treatment upregulated the expression of intercellular chemical interactions and signal transduction-related genes, similar to observations in human cells. Although HDAC inhibitors did not suppress the expression of cell cycle-related genes in CRFK cells, as observed in human cells, the inhibitors downregulated the expression of organogenesis-related genes. Consistent with observations in human cells, HDAC inhibitors suppressed the expression of cell cycle- and cancer-related genes in PG-4 cells. Importantly, valproic acid, which is thought to be more effective for neurological diseases than for cancer, suppressed the expression of more cancer-related genes in PG-4 cells than the other three HDAC inhibitors. Conclusion and relevanceOur findings revealed that the responses of cells derived from feline organs to various HDAC inhibitors varied considerably depending on the organ of origin and species. Since few studies, including human studies, have comprehensively compared transcriptomic responses to multiple HDAC inhibitor classes across multiple cell types, the results of this study provide a foundation for future research on the treatment and prevention of cancer and neurological diseases in domestic cats and other mammals.
Sforca, B. P.; Oliveira, C. B.; Furtado, M. M.; Santos, M. G.; Rocha, M. A.; Mello, M. L. S.
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Valproic acid/sodium valproate (VPA) is a widely prescribed anticonvulsant and has also been used against certain tumor cells. It is a potent modulator of gene expression. Its ability to induce apoptosis has been well documented in HeLa cells. However, another form of cell death - mitotic catastrophe - has not yet been explored in VPA-treated HeLa cells. Here, we investigated the effects of VPA treatment on mitotic catastrophe characteristics, including morphological features and their frequencies, fluorescence intensity signals of caspase-2 and p53, and the expression and abundance of DNMT1 and DNMT3B. An increased frequency of mitotic catastrophe was observed not only morphologically, but also through enhanced induction of caspase-2, involvement of p53, at least under more drastic VPA treatment, but without a decrease in DNMT1 or DNMT3B levels. Additionally, enhancement of mitotic catastrophe coincided with a reduction in mitotic chromosome abnormalities. Increased DNMT3B expression following VPA action, may be favored by previously reported chromatin decondensation induced by this drug. Enhanced CpG methylation of specific DNA sites could thus be promoted. In conclusion, VPA was shown to trigger metabolic pathways linked to different forms of cell death in HeLa cells, supporting its oncosuppressive potential.
Lopachev, A. V.; Abaimov, D. A.; Kulikova, O.; Rogneda, K.; Fedorova, T.; Khutorova, A.
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Therapy of ischemic stroke is currently limited to pharmacological and/or mechanical recanalization. There are no neuroprotective therapies approved for use during the rehabilitative phase of ischemic stroke, which is characterized by neurodegenerative changes. Thus, the search for neuroprotective compounds capable of preventing neuronal death caused by pathogenetic cascades triggered during hypoxia is an urgent task. In this study, we demonstrate increased culture viability following pre- and post-incubation with salicyl-carnosine (SC) in a model of oxygen glucose deprivation on a primary culture of rat cortical neurons. Its neuroprotective properties were greater than that of acetylsalicylic acid and carnosine, and it was effective in lower concentrations. In addition, SC protected the culture from NMDA-induced excitotoxicity. We also showed the passage of SC into neurons, and the presence of its direct antioxidant activity in a model of paraquat-induced oxidative stress. The neuroprotective effects of SC are associated with a decrease in the level of pro-apoptotic protein Bak and a decrease in the activation of kinase p38, as well as an increase in the activation of kinase ERK1/2. The acquired data suggests that SC is a promising neuroprotective compound, and warrants further investigation in vivo.
Van Baelen, A. C.; Poteaux, C.; Robin, P.; Iturrioz, X.; Panek, S.; Sewald, N.; Servent, D.; Tonali, N.
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Reliable in vitro evaluation of amyloid-{beta} (A{beta}) toxicity is essential for the development of anti-amyloid therapeutics, yet experimental workflows often lack standardization. In our previous work, we established a reproducible protocol for the synthesis, characterization and controlled aggregation of highly pure A{beta}1-42. Here, we address the biological component of this variability by evaluating the impact of neuronal differentiation and toxicity assays on A{beta}-induced neurotoxicity. SH-SY5Y cells were differentiated using retinoic acid and brain-derived neurotrophic factor, generating a neuron-like phenotype validated by immunofluorescence, gene expression profiling and resistance to H2O2-induced oxidative stress. Using this characterized model, we investigated the effects of non-aggregated and pre-aggregated A{beta}1-42 species on cell viability and transcriptional responses. Strikingly, A{beta} toxicity was highly dependent on the aggregation state of the peptide, the differentiation status of the target cells and the viability assay employed. Our results suggest that the lack of standardization in peptide quality, aggregation procedures, neuronal maturation and toxicity assessment represents a major source of variability in the amyloid field. Together, these findings provide a methodological framework to improve the reproducibility and translational relevance of in vitro screening strategies for anti-amyloid therapeutics.
Lemeshova, A.; Abdirahaman, F.; Haidari, H.; Zhao, C.; Limbada, A.; Honeycutt, J. A.
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Treatment-resistant depression and anxiety remain major challenges in psychiatry, particularly in female patients, who are disproportionately affected yet remain underrepresented in preclinical ketamine research. The present study investigated short- and long-term anxiolytic effects of acute subanesthetic ketamine administration in female Wistar-Kyoto (WKY) rats, a validated genetic model of treatment-resistant affective dysfunction. Subjects received a single intraperitoneal injection of saline vehicle or racemic ketamine (5, 10, or 15 mg/kg), followed by acoustic startle response (ASR) testing 24 hours and 7 days later. Oxidative stress was assessed using 8-oxo-2'-deoxyguanosine (8-oxo-dG) immunofluorescence in the basolateral amygdala (BLA), prefrontal cortex (PFC), and hippocampus, alongside analysis of parvalbumin-positive (PV+) interneurons. Ketamine treatment produced dose- and time-dependent behavioral effects with 10 mg/kg eliciting the strongest delayed anxiolytic-like response at 7 days, while 15 mg/kg showed more immediate behavioral effects at 24 hours. While ketamine did not alter PV+ cell count, it significantly increased oxidative stress markers globally in the BLA and prelimbic region of the PFC and specifically in the PV+ interneurons in the BLA. The findings suggest that ketamine's therapeutic effects in female WKY rats may involve region-specific modulation of stress circuitry and oxidative signaling rather than gross interneuron loss. Overall, the study provides evidence for sex-dependent and temporally dynamic effects of ketamine in a translational model of treatment-resistant anxiety and depression.
Hilares, D. J. F.; Forti, F. L.
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Emerin (EMD), an inner nuclear membrane protein essential for nuclear architecture integrity, gene expression, cellular signaling, and chromatin stability, interacts with the LINC complex and participates in cytoskeleton-nucleoskeleton communication by binding to nuclear actin filaments. EMD is implicated in migration, invasion, and metastasis in some tumors, but its role in glioblastoma (GBM) remains unclear. This study evaluated the effects of EMD knockdown and overexpression in GBM cell lines following genotoxic treatment with cisplatin. In both wild-type p53 (U87-MG) and mutant p53 (U138-MG) GBM cells, EMD expression is high, and cisplatin treatment did not affect these protein levels. EMD knockdown in U87-MG cells significantly increased cisplatin IC50, viability, and proliferation. Conversely, stable overexpression of EMD in U87-MG cells led to reduced cisplatin IC50, viability, proliferation, and migration. EMD knockdown or overexpression did not affect any U138-MG phenotypes, with or without cisplatin treatment. Modulation of EMD levels causes morphological changes in stress fiber cytoskeleton, whereas overexpression of EMD in U87-MG cells promotes an increase and a decrease in nuclear and cytoplasmic actin levels, respectively. These biological responses of U87-MG cells overexpressing EMD were coincidentally associated with alterations in the levels of pH2AX(Ser139), p-p53(Ser15), p53, and p21Kip1 proteins after cisplatin exposure. In sum, modulation of EMD levels affects the viability, migration, and proliferation of wild-type p53 GBM cells treated with cisplatin, suggesting unknown roles in the DNA damage response and repair. This work highlights EMD as a potential regulator of GBM chemoresistance and a target for therapeutic intervention.
Bento, M.; Guerreiro-Pinto, V.; Gil, M.; Rodrigues, N. C.; Cunha-reis, D.
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Tackling developmental changes in long-term potentiation (LTP) expression during adolescence is crucial to understand disease susceptibility in neurodevelopmental disorders, epileptogenesis or drug abuse. This paper investigated the alterations in the resting phosphorylation state of synaptic proteins essential for synaptic transmission and hippocampal LTP expression from weaning (3 weeks) to adulthood (12 weeks). Synaptic AMPA GluA1 and GluA2 subunit levels increased, yet to different extents, as the GluA1/GluA2 ratio also increased. Conversely, GluA1 phosphorylation in both Ser831 and Ser845 progressively decreased from weaning to adulthood, suggesting an enhanced availability of these sites for activity-dependent phosphorylation. In accordance, LTP induced by different theta-burst stimulation (TBS) intensities in the CA1 area of rat hippocampal slices enhanced gradually in this developmental period. In contrast, basal phosphorylation of GluN1, GluN2B and CaMKII increased during adolescence. Altogether, these findings suggest that alterations in AMPA receptor subunit composition and basal phosphorylation are crucial for the maturation of hippocampal LTP during adolescence, while a mild enhancement in synaptic CaMKII levels may further provide the necessary structural support to LTP expression and stability. Given the reported involvement of GluA1 phosphorylation changes in epileptogenesis and neurodevelopmental disorders, these findings provide important insights into hippocampal synaptic plasticity in normal and altered brain development and epileptogenesis.
Gerin-Lajoie, A.; Frigon, E.-M.; Adame-Gonzalez, W.; Dadar, M.; Boire, D.; Maranzano, J.
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Background: Brain banks usually provide small tissue blocks fixed by immersion in neutral-buffered formalin (NBF). While still underexploited for research, gross anatomy laboratories could provide full brains fixed by perfusion with solutions better suited for gross anatomy dissection. However, the chemicals in these solutions might have a different impact on histology protocols for cell quantification than in NBF-fixed brains. The main goal of this study is to compare the effects on the number and size of labeled neurons of the primary motor cortex (PMC) of mouse brains fixed with three different solutions: (1) NBF, typical of brain banks, (2) a saturated salt solution (SSS), and (3) an alcohol-formaldehyde solution (AFS), both used in human anatomy laboratories. Methods: 27 C57BL/6J mouse brains were perfused with the NBF (N=9), SSS (N=9) or AFS (N=9), then cut in 40-m slices and processed with immunohistochemistry to target neurons. Various quantitative variables were assessed manually and automatically on photomicrographs of 3 regions of interest (ROIs) of the PMC per specimen, namely the total and individual neuronal profile areas, number and diameters. The effects of the three fixatives on these variables were compared using ANOVA or Kruskal-Wallis, depending on the distribution. For measures on individual cells, a generalized linear mixed model was applied. Dice coefficients and correlations were applied to evaluate the agreement of the manual and automatic methods. Results: There was no significant difference between the brains fixed by the three fixatives for the total and individual cell areas, the total cell count and the cell diameters. The values obtained from manual and automatic measures had an overall good agreement (Dice coefficients > 0.79). Conclusion: It was found that the SSS and AFS had similar impacts on the quantitative variables in the tissue as the NBF. These results are promising for neuroscientists interested in using brains from anatomy laboratories for quantitative research on neurons from the PMC.
Sautreuil, C.; Lesueur, C.; Pinto Cardoso, G.; Bruel, H.; Biran, V.; Muller, J.-B.; Duigou, A.-L.; Datin-Dorriere, V.; Verspyck, E.; Marguet, F.; Laquerriere, A.; Gressens, P.; Gonzalez, B.; Marret, S.
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Prenatal alcohol exposure (PAE) is a major cause of neurodevelopmental disorders, yet most children are diagnosed late or misdiagnosed. Neuroplacentology suggest that placental factors released into maternal and/or umbilical cord blood contribute to fetal brain development. Consistently, a preclinical inter-organ transcriptomic database revealed that PAE disrupts the expression ratio of angiogenic and inflammatory factors suggesting an angio-inflammatory response. This study aimed i) to assay, by multiplex immunoassay, angiogenic and inflammatory factors in maternal and umbilical cord blood from alcohol-consuming women and ii) to perform a maternofetal analysis according to neonatal sex. Afterwards, dysregulated factors from mothers who gave birth to females or males were submitted to STRING and ShinyGO analyses. Results showed that PAE differently altered the distribution profiles of dysregulated angiogenic and inflammatory factors in maternal and umbilical cord blood. Moreover, sex-specific differences were observed, with 36% of dysregulated proteins specific to males, 48% to females, and 16% common to both. STRING analysis revealed robust functional protein-protein interactions linking together inflammatory and angiogenic clusters while the ShinyGO analysis identified enriched pathways related to vascular shear stress. These findings provide the first maternofetal analysis of combined angiogenic and inflammatory factors from alcohol-consuming mothers.
Galan-Llario, M.; Chen, H.; Legge, E.; Erikson, C. M.; Vlkolinsky, R.; Almeida, J.; Bajo, M.; Roberto, M.; Lasek, A. W.
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Astrocytes play an important role in neuronal health. A critical function of astrocytes is to clear excess extracellular glutamate and prevent excitotoxicity. STAT3 is a transcription factor that promotes astrocyte development and astrocyte reactivity in neurodegenerative diseases and following central nervous system injury. To determine the innate molecular and behavioral functions of adult astrocyte-expressed STAT3 in a non-pathological state, we created conditional Stat3 astrocyte knockout mice (Stat3 aKO) using Stat3flox and the tamoxifen-activated Cre line, Aldh1l1-Cre/ERT2. We measured transcript levels of Gfap, a known STAT3 target gene, and glutamate transporter genes in the medial prefrontal cortex (PFC) of Stat3 aKO. Gfap, Slc1a2 and Slc17a8 transcripts were decreased in the PFC of Stat3 aKO of both sexes. GLT-1 protein, encoded by Slc1a2, was also reduced in the PFC of male Stat3 aKO. We recorded spontaneous excitatory post-synaptic currents (sEPSCs) in male Stat3 aKO and control prelimbic pyramidal neurons and found increased sEPSC amplitude, consistent with a hyper-glutamatergic state due to impaired glutamate clearance. To determine the behavioral consequences of STAT3 depletion in astrocytes, Stat3 aKO were tested for locomotor activity, anxiety-like behavior and binge ethanol consumption, behaviors linked to dysregulation of glutamate homeostasis. Stat3 aKO mice did not differ in locomotor activity or anxiety-like behavior; however, male Stat3 aKO mice consumed significantly less ethanol than controls. These results indicate that STAT3 in adult astrocytes is crucial for maintaining glutamate transporter levels in the adult brain and that astrocytic STAT3 promotes ethanol consumption in male mice. Main pointsO_LIGfap, Slc1a2 and Slc17a8 expression are lower in the cortex of Stat3 astrocyte knockout mice (Stat3 aKO) C_LIO_LIGLT-1 protein is decreased and glutamate neurotransmission is elevated in the cortex of male Stat3 aKO C_LIO_LIMale Stat3 aKO consume less ethanol C_LI
Kudryavtseva, N. N.; Smagin, D. A.; Kovalenko, I. L.; Popova, N. A.; Pavlova, M. B.
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It has been previously shown that chronic social defeat stress caused by paired agonistic interactions between male mice is accompanied by the development of depression-like state and immune deficiency. The aim of this study was to investigate changes in the expression of C1qtnf superfamily genes (encoding the complement component related with tumor necrosis factor) in the hypothalamus, thymus and lungs against the background of the Lewis lung adenocarcinoma growth. In the experiments, on the 5th day of social stress, male mice were injected with tumor cells into the tail vein. Chronic social stress continued for the next two weeks. The transcriptomes of the hypothalamus, thymus and lungs of mice were sequenced at the Genoanalytica Collective Center (http://genoanalytica.ru/, Moscow). Changes in the expression of the C1qtnf genes in the tissues of stressed mice were studied compared with the control and mice that were additionally injected with tumor cells. Overall, significant correlations were found between expression of most genes in each tissue of the experimental groups. In the hypothalamus of stressed animals, when tumor cells were introduced, an increase in the expression of the genes C1qtnf1, C1qtnf2, C1qtnf3, C1qtnf6 and C1qtnf7 was observed compared to controls. In the thymus of these animals, tumor cell injection increased expression of the C1qtnf1, C1qtnf5, and C1qtnf6 genes. In the lung of tumor-injected stressed mice, expression of the C1qtnf1, C1qtnf2, C1qtnf7, and C1qtnf9 genes was decreased relative to controls and non-tumor-injected depressed mice, reaching near-zero levels in some mice. Analysis of C1qtnf superfamily gene expression in the all tissues revealed negative correlations between the expression of the C1qtnf1, C1qtnf2, and C1qtnf7 genes in the hypothalamus and lungs indicating synchronization of processes against the background of social stress and Levis lung adenocarcinoma.
Masilamoni, G. J.; Villalba, R. M.; Pare, J.-F.; Smith, Y.
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The ventral motor and the centromedian (CM) nuclei receive prominent GABAergic inputs from the basal ganglia, massive glutamatergic projections from motor cortices and significant GABAergic afferents from the reticular thalamic nucleus. There is strong evidence that disrupted processing of information through these connections may contribute to the pathophysiology of the basal ganglia-thalamocortical loop in Parkinson's disease (PD). To further assess potential ultrastructural changes in synaptic connectivity and mitochondrial integrity that may contribute to these network dysfunctions, we used a 3D electron microscopic approach to determine whether the pattern of synaptic innervation and morphological integrity of dendritic mitochondria are altered in the basal ganglia-receiving parvocellular ventral anterior nucleus (VApc) and CM neurons of MPTP-treated parkinsonian monkeys. Three main conclusions can be drawn from our findings: (1) Although the overall pattern of synaptic innervation of VApc and CM neurons is not altered in parkinsonian monkeys, the volume of putative corticothalamic terminals is significantly increased in both nuclei, (2) the prevalence of corticothalamic terminals in contact with distal dendrites is several orders of magnitude higher in VApc than CM in both control and parkinsonian monkeys, (3) the complexity and ultrastructural integrity of dendritic mitochondria is altered in CM, but not in the VApc, of parkinsonian monkeys. These findings lay the foundation for future studies of changes in cortical neuromodulation of VApc and CM neurons in parkinsonism and suggest that mitochondrial defects may contribute to the degeneration of CM neurons in PD.
Huisman, G.; Caglayan, L. S.; Febo, M.; Bian, T.; Wang, Y.; Xing, C.; Bruijnzeel, A. W.
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Tobacco use is the leading preventable cause of death worldwide. Anxiety increases the risk for smoking, and smoking in turn increases the risk for anxiety disorders. There is therefore a need to identify interventions that reduce anxiety, in general and in the context of smoking, without producing sedation. Kava (Piper methysticum), a natural product with a long history of indigenous use, has been shown to have anxiolytic and calming effects and reduce nicotine withdrawal. The current study examined whether kava without the hepatotoxic flavokavains A and B (AB-free) could reduce anxiety-like behavior in mice repeatedly treated with nicotine. Male and female C57BL/6NCrl mice received either a control diet or an AB-free kava-supplemented diet and underwent two blocks of nicotine treatments. Mice underwent a first block of five every-other-day injections of nicotine (0.5 mg/kg) or saline, with open field testing after each injection, followed one week later by a nicotine challenge. A second block of injections was given using the same injection schedule, followed by a second challenge one week later, and two weeks afterward mice received a final challenge in a novel open field. During the first treatment block, AB-free kava significantly increased center time overall, an effect most pronounced in saline-treated animals, and increased locomotor activity, while nicotine decreased both measures. During the second challenge, nicotine reduced center time but not locomotor activity, and AB-free kava increased center time in saline-treated animals only. During the final challenge, nicotine reduced both measures, whereas AB-free kava increased center time regardless of nicotine treatment, and kava-treated animals also showed a near-significant increase in center entries. These results suggest that AB-free kava reduces anxiety-like behavior without inducing sedation but does not prevent nicotine-induced suppression of exploratory behavior.