Object recognition test in mice

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

JOURNAL/nrgr/04.03/01300535-202509000-00022/figure1/v/2024-11-05T132919Z/r/image-tiff Poststroke cognitive impairment is a major secondary effect of ischemic stroke in many patients; however, few options are available for the early diagnosis and treatment of this condition. The aims of this study were to (1) determine the specific relationship between hypoxic and α-synuclein during the occur of poststroke cognitive impairment and (2) assess whether the serum phosphorylated α-synuclein level can be used as a biomarker for poststroke cognitive impairment. We found that the phosphorylated α-synuclein level was significantly increased and showed pathological aggregation around the cerebral infarct area in a mouse model of ischemic stroke. In addition, neuronal α-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia, suggesting that hypoxia is the underlying cause of α-synuclein-mediated pathology in the brains of mice with ischemic stroke. Serum phosphorylated α-synuclein levels in patients with ischemic stroke were significantly lower than those in healthy subjects, and were positively correlated with cognition levels in patients with ischemic stroke. Furthermore, a decrease in serum high-density lipoprotein levels in stroke patients was significantly correlated with a decrease in phosphorylated α-synuclein levels. Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury, some of them exhibited decreased cognitive function and reduced phosphorylated α-synuclein levels. Taken together, our results suggest that serum phosphorylated α-synuclein is a potential biomarker for poststroke cognitive impairment.

A circadian behavioral analysis suite for real-time classification of daily rhythms in complex behaviors

Long-term analysis of animal behavior has been limited by reliance on real-time sensors or manual scoring. Existing machine learning tools can automate analysis but often fail under variable conditions or ignore temporal dynamics. We developed a scalable pipeline for continuous, real-time acquisition and classification of behavior across multiple animals and conditions. At its core is a self-supervised vision model paired with a lightweight classifier that enables robust performance with minimal manual labeling. Our system achieves expert-level performance and can operate indefinitely across diverse recording environments. As a proof-of-concept, we recorded 97 mice over 2 weeks to test whether sex hormones influence circadian behaviors. We discovered sex- and estrogen-dependent rhythms in behaviors such as digging and nesting. We introduce the Circadian Behavioral Analysis Suite (CBAS), a modular toolkit that supports high-throughput, long-timescale behavioral phenotyping, allowing for the temporal analysis of behaviors that were previously difficult or impossible to observe.

Anti-cis P-tau attenuates tauopathy and enhances cognitive function following global cerebral ischemia in mice

Global cerebral ischemia/reperfusion (GCI/R) induces widespread neuronal degeneration, accompanied by tauopathy in the hippocampus and profound cognitive impairment. Tau, a microtubule-associated protein highly expressed in neurons, becomes neurotoxic upon hyperphosphorylation, disrupting mitochondrial integrity and destabilizing microtubule architecture. Despite extensive efforts, no practical therapeutic approach has emerged to counter tau-related pathology. This study established a murine GCI/R model using three cycles of bilateral common carotid artery occlusion (5 min per cycle) with 5-min reperfusion intervals. The presence of cis P-tau and cognitive deficits in the hippocampus was confirmed following GCI/R. Treatment with a cis P-tau-targeted monoclonal antibody effectively prevented cognitive deterioration and attenuated ultrastructural brain damage. These findings demonstrate that GCI/R promotes pathogenic tau formation and contributes to cognitive dysfunction. Targeting cis P-tau may represent a viable therapeutic strategy to mitigate neurodegeneration and support cognitive recovery following global cerebral ischemic injury.

Intranasal α-Synuclein induces progressive behavioral impairments in mice

α-Synuclein (α-Syn) is implicated in the progression of Parkinson's disease, yet the disease's etiology remains unclear. This study aims to explore how α-Syn affects olfactory, motor, mood and cognitive functions if it initiates from the olfactory bulb. Mice were administered intranasal human AAV-α-Syn and subsequently evaluated for olfactory, motor, mood, and cognitive functions. Immunofluorescence was performed to assess dopaminergic neuronal damage. Results shown that olfactory dysfunction was evident as AAV-α-Syn-treated mice took longer to find buried pellets compared to controls at 3, 9, and 12 months post-instillation. Motor activity remained normal at 6 months but significantly declined at 9 months. Reduced tyrosine hydroxylase expression but increased amount of human α-Syn were observed in the substantia nigra at end of behavioral measurements. AAV-α-Syn mice showed reduced sucrose intake and decreased time in the center zone of the open field at 9 months. Cognitive deficits were observed in recognition function and social memory at 6 and 9 months, with impaired working memory at 12 months. Thus, intranasal AAV-α-Syn instillation in mice leads to progressive olfactory, motor, anxiety, depression-like, and cognitive dysfunctions, reflecting α-Syn pathology propagation.

Immunotherapy-related cognitive impairment after CAR T cell therapy in mice

Immunotherapies have revolutionized cancer care for many tumor types, but their potential long-term cognitive impacts are incompletely understood. Here, we demonstrated in mouse models that chimeric antigen receptor (CAR) T cell therapy for both central nervous system (CNS) and non-CNS cancers impaired cognitive function and induced a persistent CNS immune response characterized by white matter microglial reactivity, microglial chemokine expression, and elevated cerebrospinal fluid (CSF) cytokines and chemokines. Consequently, oligodendroglial homeostasis and hippocampal neurogenesis were disrupted. Single-nucleus sequencing studies of human frontal lobe from patients with or without previous CAR T cell therapy for brainstem tumors confirmed reactive states of microglia and oligodendrocytes following treatment. In mice, transient microglial depletion or CCR3 chemokine receptor blockade rescued oligodendroglial deficits and cognitive performance in a behavioral test of attention and short-term memory function following CAR T cell therapy. Taken together, these findings illustrate targetable neural-immune mechanisms underlying immunotherapy-related cognitive impairment.

A highly conserved neuronal microexon in DAAM1 controls actin dynamics, RHOA/ROCK signaling, and memory formation

Actin cytoskeleton dynamics is essential for proper nervous system development and function. A conserved set of neuronal-specific microexons influences multiple aspects of neurobiology; however, their roles in regulating the actin cytoskeleton are unknown. Here, we study a microexon in DAAM1, a formin-homology-2 (FH2) domain protein involved in actin reorganization. Microexon inclusion extends the linker region of the DAAM1 FH2 domain, altering actin polymerization. Genomic deletion of the microexon leads to neuritogenesis defects and increased calcium influx in differentiated neurons. Mice with this deletion exhibit postsynaptic defects, fewer immature dendritic spines, impaired long-term potentiation, and deficits in memory formation. These phenotypes are associated with increased RHOA/ROCK signaling, which regulates actin-cytoskeleton dynamics, and are partially rescued by treatment with a ROCK inhibitor. This study highlights the role of a conserved neuronal microexon in regulating actin dynamics and cognitive functioning.

Divergent effects of noradrenergic activation and orexin receptor 1 blockade on hippocampal structure, anxiety-like behavior, and social interaction following chronic stress

Chronic stress (Ch.S) has detrimental effects on the brain's structure and function, particularly in the hippocampus. The noradrenergic and orexinergic systems play crucial roles in the stress response and regulation of stress-related behaviors. This study aimed to investigate the interaction between noradrenergic activation and orexin receptor 1 inhibition on chronic stress-induced hippocampal alterations. The study conducted experiments on male Wistar rats, subjected to Ch.S, OXr1 blocking, noradrenergic activation, or a combination of these treatments. Plasma corticosterone level was measured using a fluorometric method. Behavioral assessment of social maze, elevated plus maze (EPM) and novel object recognition (NOR) test were performed. Then, the expression of prepro-orexin, OXr1, and glucocorticoid receptor (GR) was analyzed using semiquantitative RT-PCR. Neuronal populations were quantified through Nissl staining. The data revealed that all stress and yohimbine groups had elevated plasma corticosterone levels. Ch.S significantly altered behavior, impairing social interaction, disrupting object recognition memory and increasing anxiety-like responses in the EPM. OXr1 blocking reversed these stress-induced behavioral deficits, while yohimbine did not improve these behavioral outcomes. Chronic stress led to a significant increase in prepro-orexin, OXr1, and GR expression. While blocking OXr1 helped counteract these stress-induced changes, yohimbine failed to restore the expression levels. Ch.S reduced hippocampal neuronal populations, while OXr1 blocking partially reversed this effect, and yohimbine further recovered the reversal. These findings indicate that blocking hippocampal OXr1 can mitigate the adverse effects of chronic stress on both hippocampal structure and anxiety-like behaviors, while noradrenergic signaling appears to have differential effects on behavioral and cellular measures.

Preventive effects of xanthohumol in APP/PS1 mice based on multi-omics atlas

Alzheimer's disease (AD) is a complex disease with unknown etiology and pathogenesis. We described a combined analysis of murine proteomics and microbiomics to find potential therapeutic targets of different doses of xanthohumol (Xn), with the goal of providing a biological basis for the treatment of early AD. Xn improved the spatial learning and memory ability of APP/PS1 mice; this was associated with an increased number of newborn neurons in the subgranular zone (SGZ) and dentate gyrus (DG) and a decreased inflammatory response. 108 proteins were significantly changed after 0.5 mg/kg Xn treatment while only 72 proteins changed by 5 mg/kg Xn. Eight significant microbiota were modulated by different doses of Xn at line discriminant analysis (LDA) score 3.0, but only three of which were regulated by 0.5 mg/kg Xn at LDA score 4.0. In addition, Xn treatment could significantly regulate the pathways of neurodegeneration- multiple diseases in the hippocampus and the penicillin and cephalosporin biosynthesis and atrazine degradation pathways in the gut. Interestingly, Nefl protein validated by correlation analysis was found in the common signaling pathway. 0.5 mg/kg Xn was able to reverse the correlation between hippocampal proteins and gut microbiota. Xn treatment significantly improved cognitive function in AD transgenic mice. Different doses of Xn caused significant differences in protein expression and flora composition and abundance, suggesting that the doses of Xn should be selected with caution, and low dose may be better in the prevention of AD.

Rescue of respiratory and cognitive impairments in Rett Syndrome mice using NLX-101, a selective 5-HT1A receptor biased agonist

Rett Syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the X-linked gene encoding the methyl-CpG-binding protein 2 (MECP2). Impaired function of this transcriptional regulator leads to profound neurological defects, among which respiratory distress, motor function and cognitive disorders are prominent. Despite great advances in understanding RTT neurobiology, therapies that can meaningfully improve patients' symptoms are still needed. Here, we focused on 5-HT1A receptor-mediated serotonergic signaling as a potential therapeutical route for RTT. We report the effects of a drug candidate, NLX-101, a highly selective, biased agonist of 5-HT1A post-synaptic receptors at brainstem and cortical regions, on key phenotypes of RTT. Unrestrained whole-body plethysmography studies confirmed and extended the previous observation that single i.p. administration of NLX-101 dose-dependently reduced the occurrence and length of apneic events in Mecp2tm1.1Bird heterozygous female mice and largely corrected respiratory irregularity. Although no preservation of motor function was observed, early onset chronic administration of NLX-101 entirely prevented the cognitive deficits of the Mecp2tm1.1Bird mice both in the short and the long-term memory paradigms of the Novel Object Recognition upon 10 weeks of treatment, an effect that was maintained throughout animals' age. Similar effects were observed in the Fear Conditioning paradigm, with treated Rett mice performing as well as wild-type controls, highlighting the procognitive properties of NLX-101. This work provides compelling evidence of the therapeutic potential of targeting post-synaptic 5-HT1A receptors to improve cognitive function in patients with RTT while supporting its respiratory-rescue properties.

Aerobic exercise improves astrocyte mitochondrial quality and transfer to neurons in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a well-established hallmark of Alzheimer's disease (AD). Despite recent documentation of transcellular mitochondrial transfer, its role in the pathogenesis of AD remains unclear. In this study, we report an impairment of mitochondrial quality within the astrocytes and neurons of adult 5 × FAD mice. Following treatment with mitochondria isolated from aged astrocytes induced by exposure to amyloid protein or extended cultivation, cultured neurons exhibited an excessive generation of reactive oxygen species and underwent neurite atrophy. Notably, aerobic exercise enhanced mitochondrial quality by upregulating CD38 within hippocampal astrocytes of 5 × FAD mice. Conversely, the knockdown of CD38 diminished astrocytic-neuronal mitochondrial transfer, thereby abolishing the ameliorative effects of aerobic exercise on neuronal oxidative stress, β-amyloid plaque deposition, and cognitive dysfunction in 5 × FAD mice. These findings unveil an unexpected mechanism through which aerobic exercise facilitates the transference of healthy mitochondria from astrocytes to neurons, thus countering the AD-like progression.

Lactoferrin ameliorates cognitive impairment in D-galactose-induced aging mice by regulating the PI3K/Akt/mTOR signaling pathway and the microbiome-gut-brain axis

Lactoferrin (LF) has been shown to be effective in attenuating oxidative stress, neuroinflammation, but its potential and mechanisms in alleviating brain aging remain to be clarified. In this study, the effect of different doses of LF (L: 50, M: 500 and H: 2000 mg/kg) on D-galactose (D-gal)-induced brain aging C57BL/6 mice was evaluated. The results showed that body weight, mobility, and spatial memory capacity of aging mice were restored after LF (M & H) intervention. It also attenuated hippocampal neuronal damage and intestinal barrier damage in aging mice. LF (M & H) increased brain and serum levels of antioxidant defense enzymes (SOD, GSH, CAT) and decreased colon and serum levels of inflammatory factors (IL-1β, IL-6 and TNF-α). Western blotting results showed that LF (M & H) increased LC3II/I, Beclin1 expression, decreased p-mTOR, p-akt, and p62 expression, and restored autophagy through the PI3K/Akt/m-TOR pathway. Furthermore, LF (M & H) protected the intestinal barrier by regulating the ratio of Firmicutes/Bacteroidetes and increased levels of the beneficial metabolites short chain fatty acids (SCFAs). Notably, LF (H) exhibited the best anti-aging potential. 500 mg/kg/day LF intervention may be cost-effective in prevents brain aging by regulating the autophagy pathway and the microbiome-gut-brain axis.

Astrocytic Hevin/SPARCL-1 Regulates Cognitive Decline in Pathological and Normal Brain Aging

Dementia, characterized by loss of cognitive abilities in the elderly, poses a significant global health challenge. This study explores the role of astrocytes, one of most representative glial cells in the brain, in mitigating cognitive decline. Specifically, we investigated the impact of Hevin (also known as SPARC-like1/SPARCL-1), a secreted glycoprotein, on cognitive decline in both normal and pathological brain aging. By using adeno-associated viruses, we overexpressed Hevin in hippocampal astrocytes of middle-aged APP/PSEN mice, an established Alzheimer's disease (AD) model. Results demonstrated that Hevin overexpression attenuates cognitive decline, as evidenced by cognitive tests, increased pre- and postsynaptic markers colocalization, and altered expression of synaptic mediators, as revealed by proteomic profiling. Importantly, Hevin overexpression did not influence the deposition of Aβ plaques in the hippocampus, a hallmark of AD pathology. Furthermore, the study extended its findings to middle-aged wild-type animals, revealing improved cognitive performance following astrocytic Hevin overexpression. In conclusion, our results propose astrocytic Hevin as a potential therapeutic target for age-associated cognitive decline.

Chitosan-coated nanostructured lipid carriers for intranasal delivery of sinapic acid in Aβ1-42 induced C57BL/6 mice for Alzheimer's disease treatment

Sinapic acid (SA) is a plant-derived antioxidant that exhibits neuroprotective activity. However, its poor bioavailability in the brain limits its therapeutic application in treating Alzheimer's disease (AD). Therefore, the present study hypothesizes that coating nanostructured lipid carriers (NLCs) with a biological macromolecule like chitosan (CH-SA-NLCs) could enhance the delivery of SA for AD treatment. The CH-SA-NLCs were spherical with sizes below 200 nm, confirmed by AFM, SEM, and TEM and achieved a sustained drug release of 76.5 % in pH 6.5 simulated nasal fluid over 24 h. Moreover, the histopathology study confirmed the safety of CH-SA-NLCs, validating its suitability for intranasal administration. Not only the in vitro sustained drug release closely correlated with in vivo pharmacokinetics of CH-SA-NLCs (i.n.), demonstrating a 1.7-fold increase in SA's half-life compared to plain SA (i.v.) in plasma but also CH-SA-NLCs (i.n.) achieved a superior AUC0-∞ of 7676.32 ± 2738.55 ng/g*h with a 2.6-fold improved drug targeting efficiency of SA in the brain of BALB/c mice. These improvements resulted in significant neuroprotective effects and decreased oxidative stress and inflammatory levels in Aβ1-42-induced mice. Overall, the study highlights safe and effective intranasal delivery of SA via chitosan-coated nanocarrier as a promising AD treatment strategy.

Enhanced cognitive function in mice through intranasal delivery of sinapic acid via chitosan-coated solid lipid nanoparticles

Sinapic acid (SAc) is a plant-based antioxidant known for its neuroprotective effects. However, its therapeutic potential for Alzheimer's disease (AD) remains limited because of its low bioavailability in the brain. Therefore, the present study hypothesized safe and effective delivery of SAc using chitosan-coated solid lipid nanoparticles (Cs-SAc-SLNs) via the intranasal route for AD treatment. The characterization of Cs-SAc-SLNs using AFM, SEM, and TEM confirmed their spherical morphology with a particle size of less than 200 nm. Moreover, the Cs-SAc-SLNs demonstrated a sustained drug release of 61.3 ± 1.7 % in 24 h. Remarkably, Cs-SAc-SLNs showed significant cellular uptake (P < 0.05) than uncoated SLNs in the Neuro-2a cell line. The histopathology study using nasal mucosa demonstrated the safety of the formulation, which makes it ideal for intranasal administration. The in vitro sustained drug release is well mapped with the in vivo pharmacokinetics study, indicating a 1.7-fold increase in the half-life (t1/2) of SAc. Interestingly, the chitosan-coated Cs-SAc-SLNs (i.n.) demonstrated a superior AUC0-∞ (3128.05 ± 129.42 ng/g*h) and showed a significant enhancement in brain bioavailability (3.7-fold) in terms of drug targeting efficiency as compared to plain SAc (i.v.). This improved brain delivery contributed to substantial neuroprotective effects in Aβ1-42-induced cognitively impaired mice. The study also supported the decreased biochemical markers levels of oxidative stress, cholinergic activity, and inflammatory cytokine levels (TNF-α) in the hippocampus and cortex of Aβ1-42-injected mice. Overall, the present study highlights the safe and enhanced cognitive function using chitosan-coated SLNs for AD treatment.

Microglia aging in the hippocampus advances through intermediate states that drive activation and cognitive decline

During aging, microglia - the resident macrophages of the brain - exhibit altered phenotypes and contribute to age-related neuroinflammation. While numerous hallmarks of age-related microglia have been elucidated, the progression from homeostasis to dysfunction during the aging process remains unresolved. To bridge this gap in knowledge, we undertook complementary cellular and molecular analyses of microglia in the mouse hippocampus across the adult lifespan and in the experimental aging model of heterochronic parabiosis. Single-cell RNA-Seq and pseudotime analysis revealed age-related transcriptional heterogeneity in hippocampal microglia and identified intermediate states of microglial aging that also emerge following heterochronic parabiosis. We tested the functionality of intermediate stress response states via TGFβ1 and translational states using pharmacological approaches in vitro to reveal their modulation of the progression to an activated state. Furthermore, we utilized single-cell RNA-Seq in conjunction with in vivo adult microglia-specific Tgfb1 conditional genetic knockout mouse models to demonstrate that microglia advancement through intermediate aging states drives transcriptional inflammatory activation and hippocampal-dependent cognitive decline.

L-DOPA Induces Spatially Discrete Changes in Gene Expression in the Forebrain of Mice with a Progressive Loss of Dopaminergic Neurons

L-3,4-Dihydroxyphenylalanine (L-DOPA) is effective at alleviating motor impairments in Parkinson's disease (PD) patients but has mixed effects on nonmotor symptoms and causes adverse effects after prolonged treatment. Here, we analyzed the spatial profile of L-DOPA-induced gene expression in the forebrain of mice with an inducible progressive loss of dopaminergic neurons (the TIF-IADATCreERT2 strain), with a focus on the similarities and differences in areas relevant to different PD symptoms. The animals received a 14-day L-DOPA treatment, and 1 h after the final drug injection, a spatial transcriptome analysis was performed on coronal forebrain sections. A total of 121 genes were identified as being regulated by L-DOPA. We found that the treatment had widespread effects extending beyond the primary areas involved in dopamine-dependent movement control. An unsupervised clustering analysis of the transcripts recapitulated the forebrain anatomy and indicated both ubiquitous and region-specific effects on transcription. The changes were most pronounced in layers 2/3 and 5 of the dorsal cortex and the dorsal striatum, where a robust increase in the abundance of activity-regulated transcripts, including Fos, Egr1, and Junb, was observed. Conversely, transcripts with a decreased abundance, e.g., Plekhm2 or Pgs1, were identified primarily in the piriform cortex, the adjacent endopiriform nucleus, and the claustrum. Taken together, our spatial analysis of L-DOPA-induced alterations in gene expression reveals the anatomical complexity of treatment effects, identifying novel genes affected by the drug, as well as molecular activation in brain areas relevant to the nonmotor symptoms of PD.

5-Aminolevulinic acid improves spatial recognition memory in mice

The production of 5-aminolevulinic acid (5-ALA) is the rate-limiting step in heme biosynthesis, and is thus essential for maintaining cellular respiration and the activities of various heme-containing enzymes. Recently, it was reported that exogenous 5-ALA can alleviate cognitive impairments in animal models. To elucidate the contributions of 5-ALA to cognition and investigate the underlying molecular mechanisms, we examined the impact of 5-ALA administration on both novel objective recognition (NOR) and spatial recognition memories in male ddY mice and on long-term potentiation (LTP) in hippocampal slices isolated from these mice. Both intracerebroventricular and oral administration of 5-ALA enhanced object recognition memory as evidenced by increased time spent investigating a novel object compared to a familiar object in the NOR test. Further, oral administration of 5-ALA improved the spontaneous alternation performance in the Y-maze test. Administration of 5-ALA also increased the glutamate/GABA ratio in dorsal hippocampus, ventral hippocampus, and entorhinal cortex, brain regions essential for recognition memory. Further, direct 5-ALA administration increased the LTP of excitatory postsynaptic potentials in hippocampal slices induced by theta-burst stimulation (TBS), and this LTP enhancement was completely mitigated by pretreatment with 1-naphthyl acetyl spermine, an antagonist of Ca2+-permeable AMPA receptors lacking the GluR2 subunit (CP-AMPARs). We suggest that 5-ALA improves spatial recognition memory by enhancing the TBS-induced expression or activity of postsynaptic CP-AMPARs, resulting in greater and longer-lasting LTP. Endogenous 5-ALA appears critical for maintaining cognitive function in the mammalian central nervous system, while exogenous supplementation could be a useful strategy for the treatment of cognitive dysfunction.

Subcellular functions of tau mediate repair response and synaptic homeostasis in injury

Injury responses in terminally differentiated cells such as neurons are tightly regulated by pathways aiding homeostatic maintenance. Cancer patients subjected to neuronal injury in brain radiation experience cognitive declines similar to those seen in primary neurodegenerative diseases. Numerous studies have investigated the effect of radiation in proliferating cells of the brain, yet the impact in differentiated, post-mitotic neurons, especially the structural and functional alterations remain largely elusive. We identified that microtubule-associated tau is a critical player in neuronal injury response via compartmentalized functions in both repair-centric and synaptic regulatory pathways. Ionizing radiation-induced injury acutely induces an increase in phosphorylated tau in the nucleus where it directly interacts with histone 2AX (H2AX), a DNA damage repair (DDR) marker. Loss of tau significantly reduced H2AX phosphorylation after irradiation, indicating that tau may play an important role in the neuronal DDR response. We also observed that loss of tau increases eukaryotic elongation factor levels, a positive regulator of protein translation after irradiation. This initial response cascades into a significant increase in synaptic proteins, resulting in disrupted homeostasis. Downstream, the novel object recognition test showed a decrease in learning and memory in tau-knockout mice after irradiation, and electroencephalographic activity contained increased delta and theta band oscillations, often seen in dementia patients. Our findings demonstrate tau's previously undefined, multifunctional role in acute responses to injury, ranging from DDR response in the nucleus to synaptic function within neurons. Such knowledge is vital to develop therapeutic strategies targeting neuronal injury in cognitive decline for at risk and vulnerable populations.

Depression-like behavior is associated with changes in the meningeal lymphatic vasculature and meningeal B cells in a murine lupus model

Meningeal lymphatic vasculature (mLV) comprises a network of vessels responsible for draining immune cells and fluid from the central nervous system (CNS) into the deep cervical lymph nodes. While changes in mLV function have been implicated in several neurodegenerative disorders, its role in autoimmune diseases is less clear. Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organs. When SLE affects the CNS, it is known as neuropsychiatric lupus (NPSLE), although the status of mLV during NPSLE has not been yet evaluated. Here, by using the lupus FcγRIIb-/- murine model, we found that this model develops NPSLE along with increased mLV coverage and function at 4 mo of age. Altered B cell developmental stages were evident in this lupus mouse model. In fact, increased B cell clusters in the meninges of FcγRIIb-/- mice were also observed. These findings suggest that mLV morphology and function are increased in FcγRIIb-/- mice together with changes in the meningeal B cell population that could have an impact on NPSLE symptoms.

Longitudinal observation of radiation-induced cognitive impairment and emotional dysfunction: Based on animal model and clinical cohort

Radiation-induced cognitive impairment (RICI) and emotional disorder (RIED) are comorbidities that seriously affect the quality of life in patients with radiation-induced brain injury (RIBI). A longitudinal study was conducted to observe the occurrence and development of RICI and RIED in an RIBI animal model and a clinical cohort following intensity modulated radiotherapy (IMRT). RIBI mice and sham controls were subjected to three cycles of behavior tests for cognitive and emotional function at post-irradiation 1 week (1w), 5 weeks (5w), and 9 weeks (9w) corresponding to early, middle and late stage after radiotherapy. Additionally, 139 patients who underwent IMRT after nasopharyngeal carcinoma and were firstly diagnosed with radiation-induced brain injury were enrolled. Pre-treatment and follow-up neuropsychological assessments of cognition, anxiety and depression were completed. Compared with control, significant declines in working memory, object recognition memory and social memory were observed in RIBI mice at post-irradiation 5w and 9w. Longitudinal observations revealed that memory impairment predominantly occurred in the middle stage and persisted into the late stage. Anxiety-like behaviors were only observed at post-irradiation 9w. In the clinical cohort, RICI exhibited a parallel cumulative incidence curve and a similar median onset to RIBI. RICI predominantly occurred 2-6 years post-IMRT 2-6 and progressively deteriorated beyond 6 years while RIED gradually increased beyond 6 years after IMRT. During two-year follow-up visits, half of the patients with RICI combined with RIBI benefited from drug treatment, achieving stable or improved cognition, while the other half showed no response or experienced cognition aggravation. In summary, RICI predominantly occurred in the middle stage post-irradiation and progressed to the late stage while RIED mostly emerged in the late stage in RIBI. Consistency in the development process of RICI and RIED was observed in the animal model and the clinical cohort.

The effects of oral gestational particulate matter 10 exposure: Insights into neurodevelopmental milestones, inhibitory control, adult sociability, and object recognition

Air pollutants have been associated with various neurodevelopmental disorders, with several studies specifically linking Particulate Matter (PM) exposure to attentional and social deficits. This link is even more pronounced when exposure occurs during the prenatal period, as it can disrupt normal brain development. However, while social deficits have been extensively studied during adolescence, their impact on adult social behaviors remains largely unexplored. To investigate these effects, pregnant Wistar rats were exposed throughout gestation (GD1-GD21) to PM10 at a dosage of 200 μg/Kg/day diluted in PBS that was freely drunk. After birth, the pups were evaluated on developmental milestones such as weight progression, ocular opening, and muscular strength. In adulthood, inhibitory control was assessed using the Five Choice Serial Reaction Time Task (5-CSRTT), social behavior using the Three-Chambered Crawley's Test (3-CT), and object recognition using the Novelty Object Recognition test (NOR). The results indicated that prenatal PM10 exposure is associated with higher birth weight and poorer performance in neuromuscular tests. However, no significant differences were observed in inhibitory control (5-CSRTT) or social behavior (3-CT). Interestingly, prenatally exposed rodents showed heightened novelty responses in the NOR test. In conclusion, gestational exposure to PM10 is related to differences in neurodevelopmental milestones, including weight and muscular strength. While it does not impact adult inhibitory control or social behavior, it influences novelty recognition in later life.

Ionic and Non-Ionic Counterparts Based on Bis(Uracilyl)Alkane Moiety with Highest Selectivity Towards Acetylcholinesterase for Protection Against Organophosphate Poisoning and Treating Alzheimer's Disease

A series of bisuracils, in which uracil and 3,6-dimethyluracil moieties were bridged with a polymethylene spacer, and the uracil moiety contained a pentamethylene radical with ionic and non-ionic aminobenzyl groups, were synthesised. These bisuracils have been identified as cholinesterase inhibitors with exceptional selectivity for acetylcholinesterase (AChE) over butyrylcholinesterase (BuChE). These bisuracils, which have been identified as highly effective AChE inhibitors, demonstrated activity at nano- and sub-nanomolar concentrations, with exceptional selectivity for AChE over BuChE. In kinetic studies of lead bisuracils 2b and 3c, both compounds exhibited mixed-type inhibition against AChE and BuChE. Additionally, molecular dynamic simulations demonstrated robust and stable interactions of 2b and 3c with the binding sites of their target. Bisuracil 2b showed significant potential for protection of AChE from irreversible inhibition by paraoxon; the most effective dose of 0.01 mg/kg was shown to reduce mortality in paraoxon-poisoned mice. Bisuracil 3c effectively inhibited brain AChE activity, reversing scopolamine-induced amnesia in mice at a dose of 5 mg/kg, which indicates its potential for cognitive enhancement. These findings position ionic bisuracils as promising prophylactics against organophosphate poisoning and non-ionic bisuracils as viable candidates for Alzheimer's disease therapeutics.

Clostridioides difficile Infection in Aged Mice Decreases Memory Function, Which Can Be Protected with Alanyl-Glutamine Supplementation

BACKGROUND

Adults aged >65 face a higher risk of both Clostridioides difficile infection (CDI) and dementia. CDI in the elderly may exacerbate functional and cognitive impairments. Current CDI treatment options are limited. Alanyl-glutamine (AQ) is a dipeptide shown to decrease C. difficile toxin effects in vitro and in vivo.

OBJECTIVES

We tested the potential benefits of AQ on the clinical outcomes and cognitive impairment in the aged mouse model of CDI treated at various timings of AQ and vancomycin treatment.

METHODS

C57BL/6 retired breeder (9 mo) and aged (18 mo) mice were treated with AQ-supplemented water as a 2-wk pretreatment or continuously. The mice underwent a standard CDI protocol (VPI10463) and were treated, or not, with vancomycin. Disease severity was tracked for 14 d, then novel object recognition (NOR) tests for acute memory were performed. Hippocampal tissues were assayed for molecular markers.

RESULTS

NOR testing confirmed CDI-induced cognitive impairment (P = 0.0352). AQ pretreatment had mild neuroprotective effects during CDI. Mice treated with vancomycin and continuous AQ had better clinical scores and better memory performance than vancomycin controls (P = 0.0286). Continuous AQ treatment, when used alone or paired with vancomycin, offered protection against CDI-induced cognitive impairment. The mechanism of CDI-induced memory impairment remains unclear, but infected mice had elevated synaptobrevin-2 (P = 0.0396) and neural cell adhesion molecule (P = 0.008) compared with uninfected controls on day 14 post infection.

CONCLUSIONS

Our findings suggest that neuroinflammation and memory loss occur during CDI, which may be ameliorated by AQ supplementation. AQ supplementation may have both neurological and intestinal protective effects during CDI treatment.

Homeostatic Activation of 26S Proteasomes by Protein Kinase A Protects against Cardiac and Neurobehavior Malfunction in Alzheimer's Disease Mice

Alzheimer's Disease (AD) patients often show brain and cardiac malfunction. AD represents a leading cause of morbidity and mortality worldwide, but the demand for effective treatment for AD is far from being met. This is primarily because AD pathogenesis, including brain-heart interaction, is poorly understood. Proteasome functional insufficiency is implicated in AD; as such, proteasome enhancement promises a potentially new strategy to treat AD. The proteasome can be activated by protein kinase A (PKA) via selectively phosphorylating Ser14-RPN6/PSMD11 (p-S14-RPN6); however, whether p-S14-RPN6 is altered and what role p-S14-RPN6 plays in AD remain unclear. Hence, this study was conducted to address these critical gaps. We found that genetic blockade of the homeostatic p-S14-Rpn6 via germline knock-in of Rpn6 S14A (referred to as S14A) significantly reduced proteasome activities in the cerebral cortex but did not discernibly impair learning and memory function in 4-month-old mice or cause cardiac dysfunction before 12 months of age. Increases in Ser14-phosphorylated Rpn6 in the cerebral cortex and markedly elevated Aβ proteins in the myocardium were observed in young 5XFAD mice, a commonly used AD model. When introduced into the 5XFAD mice, S14A significantly aggravated the learning and memory deficits as revealed by the radial arm water maze tests and accelerated cardiac malfunction as measured by serial echocardiography in the same cohort of 5XFAD mice. Thus, the present study establishes for the first time that homeostatic activation of 26S proteasomes by basal p-S14-RPN6 or PKA activity protects against both the brain and heart malfunction in the 5XFAD mice.

The activation of the piriform cortex to lateral septum pathway during chronic social defeat stress is crucial for the induction of behavioral disturbance in mice

Chronic stress induces neural dysfunctions and risks mental illnesses. Clinical and preclinical studies have established the roles of brain regions underlying emotional and cognitive functions in stress and depression. However, neural pathways to perceive sensory stimuli as stress to cause behavioral disturbance remain unknown. Using whole-brain imaging of Arc-dVenus neuronal response reporter mice and machine learning analysis, here we unbiasedly demonstrated different patterns of contribution of widely distributed brain regions to neural responses to acute and chronic social defeat stress (SDS). Among these brain regions, multiple sensory cortices, especially the piriform (olfactory) cortex, primarily contributed to classifying neural responses to chronic SDS. Indeed, SDS-induced activation of the piriform cortex was augmented with repetition of SDS, accompanied by impaired odor discrimination. Axonal tracing and chemogenetic manipulation showed that excitatory neurons in the piriform cortex directly project to the lateral septum and activate it in response to chronic SDS, thereby inducing behavioral disturbance. These results pave the way for identifying a spatially defined sequence of neural consequences of stress and the roles of sensory pathways in perceiving chronic stress in mental illness pathology.

The impact of oral cannabis consumption during pregnancy on maternal spiral artery remodelling, fetal growth and offspring behaviour in mice

BACKGROUND

The use of cannabis during pregnancy is rising following its widespread legalization. Cannabidiol (CBD) is gaining popularity due to the public perception that it is safer than the psychoactive cannabis component Δ9-tetrahydrocannabinol (THC). However, while evidence underpins the harm of THC and cannabis smoke on fetal development, there is minimal research on the safety of CBD and oral cannabis. The current study aims to decipher the safety of oral CBD and THC use during pregnancy.

METHODS

Using a mouse model, we directly compared the effects of oral CBD and THC oil exposure (20 mg/kg body weight) from early to mid-gestation on implantation site remodelling and fetal growth. We examined offspring behaviour and metabolic activity using both traditional and automated cage systems. Lastly, using human and mouse immune cells we assessed how CBD and THC influence angiogenic factor production.

FINDINGS

We observed impaired maternal spiral artery remodelling in cannabis exposed mice and found that CBD and THC disrupt immune cell angiogenic factor production. Oral consumption of THC or CBD oil also resulted in significant fetal growth impairment and led to long-lasting sex-dependent consequences as male offspring exhibited altered aggression and metabolic activity while females had impaired spatial learning.

INTERPRETATION

Our results show that oral consumption of either CBD or THC oil during pregnancy in mice results in harm to the developing fetus and causes behavioural changes after birth.

FUNDING

The Michael G. DeGroote Centre for Medicinal Cancer Research, the Canadian Institutes of Health Research, and the Canadian Foundation for Innovation.

Acute Administration of Edaravone Improves Cognitive Impairment in a Mouse Model of mPFC Ischemia: Crosstalk Between Necroptosis, Neuroinflammation, and Antioxidant Defense

Edaravone (Eda), a well-known free radical scavenger, has been reported as a possible therapeutic agent for ischemic stroke patients' recovery. This study aimed to investigate the effects of time-dependent treatment with Eda on medial prefrontal cortex (mPFC) ischemia. Mice were randomly allocated into six groups: control, sham, normal saline, Eda-I, Eda-II, and Eda-III. After induction of a photothrombotic ischemia in the mPFC region, Eda-I, Eda-II, and Eda-III groups received 3 mg/kg Eda intraperitoneally at the times of 0, 2, and 6 h post-surgery. After 1 day of recovery, the mice underwent behavioral tests (open field, novel object recognition, and T-maze). Next, necroptosis, NOD-like receptor protein 3 (NLRP3), and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-related protein levels were measured in the lesioned area using western blot analysis. For double confirmation, IL-1β and IL-18 were also assessed by immunofluorescence in the area. Further, histological evaluations were performed to measure tissue damage. The results showed that mPFC ischemia impaired recognition and spatial working memory without affecting locomotor activity, while immediate Eda administration improved cognitive impairments. Furthermore, acute Eda treatment reduced RIP1, RIP3, and MLKL levels, inhibited NLRP3 inflammasome proteins (NLRP3, ASC, and Cas1), decreased IL-1β and IL-18, upregulated Nrf2 and its targets (NQO-1 and HO-1), and diminished tissue damage. Our results highlighted the effects of acute administration of Eda post-stroke on improving cognitive impairments by suppressing necroptosis and NLRP3 inflammasome pathways and activating the Nrf2 antioxidant defense mechanism.

Cannabidiol reverses myeloperoxidase hyperactivity in the prefrontal cortex and striatum, and reduces protein carbonyls in the hippocampus in a ketamine-induced schizophrenia rat model

BACKGROUND

Schizophrenia (SCZ) has limited treatment options, often with significant side effects. Cannabidiol (CBD), a non-euphoric phytocannabinoid, has shown potential as a novel therapeutic option in SCZ due to antipsychotic-like, anti-inflammatory, and antioxidant properties. We compared the therapeutic effects of CBD and risperidone (RISP) in a rat model of SCZ induced by sub-chronic ketamine (KET), focusing on inflammatory and oxidative stress, and behavioral phenotypes.

METHODS

Rats were pre-treated with KET or saline (SAL) for 10 days followed by CBD or RISP for 8 days. Locomotion, anxiety- and anhedonia-like behavior, and recognition memory were assessed. Oxidative damage as measured by protein carbonyls, thiobarbituric acid reactive substances, and catalase activity, and the inflammation markers myeloperoxidase (MPO) activity and nitrite/nitrate (N/N) concentration ratio were assessed in the prefrontal cortex (PFC), hypothalamus (HYP), hippocampus (HPC), and striatum, brain areas relevant to SCZ.

RESULTS

CBD restored the KET-induced decreased rearing behavior in the OFT, while RISP further decreased rearing. RISP treatment in control rats decreased rearing and elicited an anhedonic-like phenotype, while CBD did not. CBD, but not RISP restored the KET-induced increased levels of MPO activity in the PFC and the striatum, and protein carbonyls in the HPC. Post-KET treatment with RISP but not CBD decreased protein carbonyls in the PFC, and decreased the N/N concentration ratio in the HYP.

CONCLUSION

CBD restored the KET-induced decrease in rearing behavior without inducing an anhedonic-like phenotype as observed with RISP. CBD, and to a lesser extent RISP restored the oxidative stress and neuroinflammation elicited by KET in the striatum, HPC, and PFC. These findings support the possibility that the antipsychotic effects of CBD might be mediated by its antioxidant and anti-inflammatory effects.

Sleep fragmentation impairs cognitive function and exacerbates Alzheimer's disease-related pathology in a mouse model by disrupting mitochondrial biogenesis

A large proportion of Alzheimer's disease (AD) patients suffer from various types of chronic sleep disturbances, including sleep fragmentation (SF). In addition, impaired mitochondrial biogenesis is an important feature of AD, but whether it is altered in sleep disorders has not been fully elucidated. Hence, we aimed to investigate the relationship between SF and mitochondrial biogenesis and the possible impact of SF on AD-related pathology. In this study, thirty-six 9-month-old 3xTgAD model mice and thirty-six 9-month-old wild-type (WT) C57BL/6 J mice were divided into a control group (6 weeks of normal sleep), a SF group (6 weeks of SF) and a SF + recovery sleep group (6 weeks of SF followed by 2 weeks of recovery sleep). Cognitive functions were assessed by behavioural experiments. Mitochondrial structure and function and the activity of a classic mitochondrial biogenesis signalling pathway were investigated using transmission electron microscopy (TEM), reverse transcription quantitative polymerase chain reaction (RT-qPCR), immunofluorescence and Western blotting. Markers of AD-related pathology, including the levels of amyloid β (Aβ) and tau proteins, were assessed by immunofluorescence and Western blotting. The expression of insulin-degrading enzyme (IDE) was assessed by Western blotting. We found that long-term SF impaired the cognitive functions of the mice. In addition, chronic SF reduced the expression of mitochondrial respiratory chain components, the number of mitochondria, the fluorescence intensity of COX-IV, the level of mitochondrial DNA (mtDNA) and the expression of crucial regulators of the AMPK/SIRT-1/PGC-1α signalling pathway in the mouse prefrontal cortex and hippocampus, while recovery sleep could partly abrogate these effects. Moreover, SF reduced the protein level of IDE and increased the Aβ burden and tau hyperphosphorylation. This study demonstrates that chronic SF can negatively regulate the AMPK/SIRT-1/PGC-1α signalling pathway to disrupt mitochondrial biogenesis in the brains of mice, which may subsequently exacerbate AD-related pathology by decreasing the expression of IDE.

IKKβ inhibits cognitive memory and adult hippocampal neurogenesis by modulating the β-catenin pathway

AIM

The IKKβ signaling pathway regulates NF-κB, influencing inflammation and cell survival in the brain. Radial glia cells are crucial for hippocampal neurogenesis and cognition. However, the role and mechanisms of IKKβ in modulating radial glia behavior and its impact on memory and neurogenesis remain unclear. Further studies are needed to understand how alterations in this pathway affect hippocampal function.

MAIN METHODS

The role of IKKβ in memory and hippocampal neurogenesis was examined using GFAP-CreERT2/IKKβflox/flox mice with IKKβ knockdown in radial glia cells. IKKβ expression, NSC proliferation, and differentiation were assessed by immunohistochemistry. NF-κB and β-catenin interactions were evaluated by immunoprecipitation. Cultured adult hippocampal NSCs, with IKKβ or β-catenin shRNA transfection, were analyzed by flow cytometry and western blot to examine stem cell characteristics, NF-κB signaling, cell cycle, and β-catenin pathways.

KEY FINDINGS

Our results showed IKKβ cKD increased exploratory activity in the open-field and hyperactivity in the Y-maze, as well as enhanced spatial memory in the object location and Morris water maze tests. It also promoted adult hippocampal NSC proliferation by upregulating positive and inhibiting negative cell cycle regulators. Neuronal differentiation was enhanced, affecting β-catenin signaling and NeuroD1 expression. Additionally, IKKβ cKD promoted NSC survival, as shown by decreased cleaved caspase-3 and reduced Bax and cytochrome c in the hippocampus.

SIGNIFICANCE

These findings suggest that in hippocampal NSCs, IKKβ inhibits locomotion, cognitive function, and adult hippocampal neurogenesis by suppressing the β-catenin signaling, highlighting its key role in decreasing hippocampal neurogenesis and cognitive function through NF-κB signaling in adult NSCs.

Glutamate transporter activator LDN-212320 prevents chronic pain-induced cognitive impairment and anxiety-like behaviors in a mouse model

The astroglial glutamate transporter in the hippocampus and anterior cingulate cortex (ACC) is critically involved in chronic pain-induced cognitive and psychiatric abnormalities. We have previously reported that LDN-212320, a glutamate transporter-1 (GLT-1) activator, attenuates complete Freund's adjuvant (CFA)-induced acute and chronic nociceptive pain. However, the cellular and molecular mechanisms underlying GLT-1 modulation in the hippocampus and ACC during chronic pain-induced cognitive deficit-like and anxiety-like behaviors remain unknown. Here, we have investigated the effects of LDN-212320 on CFA-induced chronic pain associated with cognitive deficit-like and anxiety-like behaviors in mice. We have evaluated the effects of LDN-212320 on CFA-induced impaired spatial, working, and recognition memory using Y-maze and object-place recognition tests. In addition, we have determined the effects of LDN-21230 on chronic pain-induced anxiety-like behaviors using elevated plus maze and marble burying test. We have also examined the effects of LDN-212320 on cAMP response element-binding protein (pCREB), brain-derived neurotrophic factor (BDNF), protein kinase A (PKA), and Ca2 +/calmodulin-dependent protein kinase II (CaMKII) expression in the hippocampus and ACC during CFA-induced cognitive deficit-like and anxiety-like behaviors using the Western blot analysis and immunofluorescence assay. Pretreatment with LDN-212320 (20 mg/kg) significantly attenuated CFA-induced impaired spatial, working, and recognition memory. Furthermore, LDN-212320 (20 mg/kg) significantly reduced CFA-induced anxiety-like behaviors. Additionally, LDN-212320 (20 mg/kg) significantly reversed CFA-induced decreased pCREB, BDNF, PKA and CaMKII expression in the hippocampus and ACC. Overall, these results suggest that the LDN-212320 prevents CFA-induced cognitive deficit-like and anxiety-like behaviors by activating CaMKII/CREB/BDNF signaling pathway in the hippocampus and ACC. Therefore, LDN-212320 could be a potential treatment for chronic pain associated with cognitive impairment and anxiety-like behaviors.

Medium-chain triglycerides tricaprin TC10 and tricaprylin TC8 attenuated HFD-induced cognitive decline in a manner dependent on or independent of GLP-1

Population aging is the most important social and medical demographic issue worldwide; therefore, healthy aging is important. The increasing prevalence of dementia and cognitive decline are major health concerns. Medium-chain triglycerides (MCTs) have been shown to improve cognitive decline. The present study investigated the effects and mechanisms of action of orally administered MCTs, including tricaprylin (TC8), tricaprin (TC10), and trilaurin (TC12), on cognitive function in mice fed a high-fat diet (HFD). The administration of TC8 and TC10 attenuated cognitive decline. A relationship has been reported between cognitive dysfunction and impaired glucose metabolism. The administration of TC8 and TC10 also reduced blood glucose levels in the glucose tolerance test. Cognitive improvements by MCTs are widely attributed to the ketogenic effect. In the present study, TC8 significantly increased blood ketone concentrations, whereas TC10 did not. On the other hand, TC10 increased the plasma concentration of glucagon-like peptide-1 (GLP-1), the hormone that promotes insulin secretion. The administration of the GLP-1 receptor antagonist, exendin(9-39), blocked the cognitive-enhancing effects of TC10. These results suggest that TC10 improved cognitive function via the GLP-1 receptor. The in vitro experiment indicated that 2-monocaprin (2-MC10), not TC10, stimulated the secretion of GLP-1 and decreased intracellular cAMP concentrations. In conclusion, we herein demonstrated that TC8 and TC10 attenuated cognitive decline through different mechanisms. This is the first study to suggest that TC10 attenuates cognitive decline via GLP-1.

The E3 Ubiquitin Ligase PRAJA1: A Key Regulator of Synaptic Dynamics and Memory Processes with Implications for Alzheimer's Disease

The precise regulation of synaptic function by targeted protein degradation is fundamental to learning and memory, yet the roles of many brain-enriched E3 ubiquitin ligases in this process remain elusive. Here, we uncover a critical and previously unappreciated role for the E3 ubiquitin ligase PRAJA1 in orchestrating synaptic plasticity and hippocampus-dependent memory. Utilizing C57BL/6 and 5xFAD male mice and employing a multi-faceted approach including protein biochemistry, molecular biology, in vitro electrophysiology, and behavioral assays, we demonstrate that long-term potentiation (LTP) induction triggers a rapid, proteasome-dependent downregulation of PRAJA1 within the CA1 region of the hippocampus. Critically, selective knockdown of PRAJA1 in vivo profoundly enhanced both object recognition and spatial memory, while disrupting normal exploratory behavior. Mechanistically, we reveal that PRAJA1 acts as a key regulator of synaptic architecture and transmission: its downregulation leads to a reduction in key synaptic proteins and spine density, influencing the excitatory/inhibitory balance and facilitating synaptic plasticity. Conversely, increased PRAJA1 expression potentiates GABAergic transmission. Furthermore, we identify spinophilin as a novel substrate of PRAJA1, suggesting a direct molecular link between PRAJA1 and synaptic remodeling. Strikingly, our findings implicate dysregulation of PRAJA1 in the pathogenesis of Alzheimer's disease, positioning PRAJA1 as a potential therapeutic target for cognitive enhancement in neurodegenerative conditions. These results unveil PRAJA1 as a critical molecular brake on synaptic plasticity and memory formation, offering a promising new avenue for understanding and potentially treating memory impairment.

Vagus nerve stimulation -induced anxiolytic and neurotrophic effect in healthy rats

Memory, learning, anxiety, and depression have concerned science for years, increasingly leading to research into new therapeutic targets. The study investigated the effect of acupuncture stimulation of the auricular branch of the vagus nerve (ABVN) on memory, anxiety-like and depression-like behaviors in healthy rats. Healthy rats were divided into groups: (1) control, without treatment; (2) acupuncture in the left ABVN; and (3) acupuncture in the right ABVN. Tests were conducted to evaluate memory (inhibitory avoidance and object recognition), anxiety-like (open field, elevated plus maze, and light/dark box), and depressive-like (sucrose preference and forced swimming) behaviors. In addition, the concentration of brain-derived neurotrophic factor (BDNF) in the hippocampus of the rats was evaluated. The control group did not show any changes in the behavioral tests. The animals that received acupuncture (ABVN-R and ABVN-L) remained longer on the light side of the light/dark box test compared to the control group. Acupuncture in the ABVN-R also increased the concentration of BDNF in the hippocampus of the animals. Accordingly, acupuncture stimulation of the ABVN did not show an antidepressant effect or improve memory in healthy animals; however, it did show an anxiolytic effect and increased neurotrophic levels in the hippocampus.

CD147-CAR-NK cell therapy shows minimal toxicities in human CD147 transgenic mouse model with solid tumors

The toxicity of chimeric antigen receptor-natural killer (CAR-NK) therapy has not been tested in solid tumors, compared with CAR-T therapy side by side. To address this, we investigated the CD147-CAR-NK "on-target/off-tumor" toxicity and neurotoxicity in human CD147-transgenic (hCD147TG) mice with hepatocellular carcinoma (HCC). We first tested the in vitro cytotoxicity of CD147-CAR-NK against CD147+ tumor and CD147+ healthy cells. Both CD147-CAR-NK cells and CD147-IL15-CAR-NK (autocrine expressing interleukin [IL]-15) can kill tumor cells specifically but not CD147+ healthy lung and spleen tissue from hCD147TG mice. In vivo assays show minimal systemic toxicities against CD147+ healthy tissues but 1-week-longer persistence times in tumor than non-tumor tissues. To evaluate neurotoxicity, we compared the expression of ionized calcium-binding adaptor protein 1 (IBA1), glial fibrillary acidic protein (GFAP), and inducible nitric oxide synthase (iNOS) between CD147-CAR-T- and CD147-CAR-NK-treated hCD147TG mice with HCC. Both CD147-CAR-T- and CD147-CAR-NK-treated mice exhibited higher GFAP and IBA1 expression than control groups. CD147-CAR-T-treated mice showed an increase in iNOS compared to the control groups. The behavioral studies testing spatial memory showed that mice treated with CD147-CAR-NK exhibit better memory function than CD147-CAR-T-treated mice. This study provides a deeper understanding of the CD147-CAR-NK systemic toxicities and neurotoxicity of CD147-CAR-NK relative to CD147-CAR-T therapy.

Proinflammatory cytokines, oxidative stress, and organ function as biomarkers of soman (GD) chronic neurotoxicity

Organophosphate (OP) nerve agents, such as soman (GD), pose great risk to neurological health by inhibiting acetylcholinesterase, leading to seizures, epilepsy, and behavioral deficits. While acute treatment may alleviate immediate symptoms, the long-term consequences, particularly those involving neuroinflammation and systemic toxicity, remain poorly understood. This study used adult male and female Sprague Dawley rats to investigate the chronic effects of a single acute exposure to soman (132 µg/kg, s.c., 1.2 × LD50) on neuroinflammation, behavioral comorbidity, and systemic toxicity. Following exposure, animals were treated with atropine sulfate (2 mg/kg, i.m.) and oxime HI-6 (125 mg/kg, i.m.) to mitigate peripheral cholinergic effects, and with midazolam (3 mg/kg, i.m., 1 h post-exposure) to control seizures. Spontaneously recurring seizures were monitored during handling and with video electroencephalogram (vEEG). Neurobehavioral deficits were assessed 4-8 weeks post-exposure. At 18 weeks post-exposure, brain, serum, and cerebrospinal fluid (CSF) were analyzed for inflammatory and nitro-oxidative stress markers, and the liver and kidney function biomarkers were evaluated. Soman-exposed animals developed epilepsy, confirmed by handling-induced seizures and/or continuous vEEG monitoring. Behavioral assessments revealed significant memory deficits following soman exposure. Proinflammatory cytokines (TNF-α, IL-6, IL-1α, IL-18, IL-17A, and MCP-1) were significantly elevated in both serum and CSF, alongside corresponding increases in their gene expression in the brain. Elevated reactive oxygen/nitrogen species were detected in the serum. Although hematological parameters remained unchanged, a significant increase in total bilirubin and an upward trend in serum blood urea nitrogen (BUN) levels and BUN: Creatinine ratio indicated potential liver and kidney dysfunction. However, no significant structural changes in these organs at the cellular level were observed in histological analyses. This study identifies critical chronic biomarkers of soman exposure affecting the brain, serum, CSF, liver, and kidney. The findings highlight the critical need to monitor systemic and neurological impacts, as well as organ function, to develop effective diagnostic and therapeutic strategies for survivors of nerve agent exposure or OP pesticide poisoning. Behavioral deficits and EEG changes in soman-exposed animals further emphasize the long-term neurological consequences of exposure.

Astroglial TNFR2 signaling regulates hippocampal synaptic function and plasticity in a sex dependent manner

Astrocytes participate in synaptic transmission and plasticity through tightly regulated, bidirectional communication with pre- and post-synaptic neurons, as well as microglia and oligodendrocytes. A key component of astrocyte-mediated synaptic regulation is the cytokine tumor necrosis factor (TNF). TNF signals via two cognate receptors, TNFR1 and TNFR2, both expressed in astrocytes. While TNFR1 signaling in astrocytes has been long demonstrated to be necessary for physiological synaptic function, the role of astroglial TNFR2 has never been explored. Here, we demonstrate that astroglial TNFR2 is essential for maintaining hippocampal synaptic function and plasticity in physiological conditions. Indeed, Gfap creERT2 :Tnfrsf1b fl/fl mice with selective ablation of TNFR2 in astrocytes exhibited dysregulated expression of neuronal and glial proteins (e.g., SNARE complex molecules, glutamate receptor subunits, glutamate transporters) essential for hippocampal synaptic transmission and plasticity. Hippocampal astrocytes sorted from Gfap creERT2 :Tnfrsf1b fl/fl mice displayed downregulation of genes and pathways implicated in synaptic plasticity, as well as astrocyte-neuron and astrocyte-oligodendrocyte communication. These alterations were accompanied by increased glial reactivity and impaired astrocyte calcium dynamics, and ultimately translated into functional deficits, specifically impaired long-term potentiation (LTP) and cognitive functions. Notably, male Gfap creERT2 :Tnfrsf1b fl/fl mice exhibited more pronounced hippocampal synaptic and cellular alterations, suggesting sex-dependent differences in astroglial TNFR2 regulation of synaptic function. Together, these findings indicate that TNFR2 signaling in astrocytes is essential for proper astrocyte-neuron communication at the basis of synaptic function, and that this is regulated in a sex-dependent manner.

Intrahippocampal delivery of hyperphosphorylated human tau oligomers induces neurodegeneration in non-transgenic wildtype mice

Hyperphosphorylated tau (p-tau) forms neurofibrillary tangles, a key biomarker for Alzheimer's disease and additional neurodegenerative tauopathies. However, neurofibrillary tangles are not sufficient to cause neuronal dysfunction or death. Intrahippocampal injection of tau isolated from AD patients has limited effects on the cognitive functions of non-transgenic mice, despite the recapitulation of pathological tau deposits in the mouse brain. It therefore remains uncertain as to whether all hyperphosphorylated tau is directly responsible for AD neurodegeneration. We examined this issue by injecting recombinant p-tau oligomers to the hippocampus of non-transgenic, wildtype mice and found progressive cognitive deficits that correlate with neuron death spreading from the ipsilateral hippocampus to the cortex. Apomorphine, which retards p-tau aggregation and cytotoxicity in vitro , antagonized p-tau-induced cognitive deficits and neuron death. These results suggest the pathogenic role of p-tau oligomers and a novel AD model facilitating drug development.

JNK inhibition mitigates sepsis-associated encephalopathy via attenuation of neuroinflammation, oxidative stress and apoptosis

Sepsis-associated encephalopathy (SAE) is a severe complication of sepsis, leading to cognitive dysfunction and neuronal damage. C-Jun N-terminal kinases (JNKs), a subset of the MAP kinase family, have attracted substantial interest for their role in cellular events during sepsis conditions. Previous investigations have established the involvement of JNK signaling against memory impairment and abnormal synaptic plasticity. However, the present study is the first to investigate the effects of JNK inhibition in sepsis-associated cerebral injury and cognitive impairments. This study investigated the neuroprotective effects of SP600125, a selective JNK inhibitor, in cecal ligation and puncture (CLP) mouse model of sepsis. CLP-induced sepsis resulted in significant cognitive impairments, as assessed by the open field test, inhibitory avoidance test, morris water maze, and novel object recognition test. Additionally, septic mice exhibited increased serum levels of neuronal injury markers (S100B and NSE), pro-inflammatory cytokines (TNF-α and IL-1β), and oxidative stress markers (MDA), along with decreased antioxidant levels (GSH, SOD, and CAT). Histological analysis revealed neuronal pyknosis, degeneration, and loss of Nissl bodies in the cortex and hippocampus of septic mice. Furthermore, sepsis-induced blood-brain barrier dysfunction was evident from increased cerebral edema. Treatment with SP600125 (10, 30, and 50 mg/kg) significantly attenuated CLP-induced cognitive deficits, neuronal injury, neuroinflammation, oxidative stress, and apoptosis in a dose-dependent manner. The present study provides preliminary evidence that JNK inhibition by SP600125 exerts neuroprotective effects against sepsis-induced encephalopathy in vivo via suppression of neuroinflammation, oxidative stress, and apoptosis.

Use of an oversized AAV8 vector for CPS1 deficiency results in long-term survival and ammonia control

Carbamoyl phosphate synthetase 1 (CPS1) deficiency, a urea-cycle disorder, results in hyperammonemia initiating a sequence of adverse events that can lead to coma and death if not treated rapidly. There is a high unmet need for an effective therapeutic for this disorder, especially in early neonatal patients where mortality is excessive. However, development of an adeno-associated virus (AAV)-based approach is hampered by large cDNA size and high protein requirement. We developed an oversized AAV vector as a gene therapy to treat CPS1 deficiency. In order to constrain genome size, we utilized small liver-specific promoter/enhancers and a minimal polyadenylation signal. Long-term survival (9 months, end of study) with ammonia control was achieved in AAV8.CPS1-administered Cps1flox/flox mice, while all null vector-injected controls died with marked hyperammonemia; female mice demonstrated improved survival over treated males. While glutamine remained elevated compared to controls, ammonia was controlled in surviving animals. Mice maintained their weights and were not sarcopenic. While drinking water did contain carglumic acid, no nitrogen scavengers were administered. Although there were concerns with vector genomic integrity, these findings demonstrate proof of concept for an oversized gene-therapy approach for a challenging urea-cycle disorder where high-level hepatic protein is essential for survival.

Carbon ion stimulation therapy reverses iron deposits and microglia driven neuroinflammation and induces cognitive improvement in an Alzheimer's disease mouse model

Insoluble iron deposits often exist as iron oxide nanoparticles in protein aggregates, impaired ferritin, or activated microglia and have been implicated as major causes of neuroinflammation in Alzheimer's disease. However, no crucial evidence has been reported to support the therapeutic effects of current iron chelators on the deposition of various molecular forms of insoluble iron. We investigated the therapeutic effect of carbon ion stimulation (CIS) via a transmission beam on insoluble iron deposits, iron inclusion bodies, and the associated biological response in 5xFAD AD mouse brains. Compared with no treatment, CIS dose-dependently induced a 33-60% reduction in the amount of ferrous-containing iron species and associated inclusion bodies in the brains of AD mice. CIS induced considerable neuroinflammation downregulation and, conversely, anti-inflammatory upregulation, which was associated with improved memory and enhanced hippocampal neurogenesis. In conclusion, our results suggest that the effective degradation of insoluble iron deposits in combination with pathogenic inclusion bodies promotes AD-modifying properties and offers a potential CIS treatment option for AD.

Melatonin Alleviates Behavioral and Neurodevelopmental Abnormalities in Offspring Caused by Prenatal Stress

BACKGROUND

Prenatal stress (PNS) is a significant risk factor impacting the lifelong health of offspring, and it has been widely recognized as being closely linked to the increased prevalence of neurodevelopmental disorders and psychiatric illnesses. However, effective pharmacological interventions to mitigate its detrimental effects remain limited. Melatonin (Mel), an endogenous hormone, has demonstrated considerable potential in treating neurological diseases due to its anti-inflammatory, antioxidant, and neuroprotective properties, as well as its favorable safety profile and broad clinical applicability.

OBJECTIVE

This study aims to investigate the protective effects and mechanisms of melatonin on neurodevelopmental and behavioral abnormalities in offspring induced by prenatal stress.

METHODS

Using a prenatal stress mouse model, we evaluated the effects of melatonin on emotional and cognitive deficits in offspring. Neurogenesis and synaptic development were assessed, and RNA sequencing was performed to analyze microglial gene enrichment and immune-related pathways. Both in vivo and in vitro experiments were conducted to validate the findings, focusing on the PI3K/AKT/NF-κB signaling pathway in microglia.

RESULTS

Melatonin administration alleviated emotional and cognitive deficits in offspring mice exposed to prenatal stress, addressing abnormalities in neurogenesis and synaptic development. Additionally, RNA sequencing revealed that melatonin suppresses microglial gene enrichment and the upregulation of immune-related pathways. Both in vivo and in vitro validation indicated that melatonin modulates the PI3K/AKT/NF-κB signaling pathway in microglia, reducing the elevated expression of CXCL10 in the dentate gyrus, thereby restoring normal neuro-supportive functions and optimizing the neurodevelopmental environment.

CONCLUSION

These findings suggest that melatonin significantly improves neurodevelopmental disorders and behavioral abnormalities caused by prenatal stress by inhibiting pathological microglial activation and promoting hippocampal neurogenesis and synaptic plasticity. This provides new insights into melatonin's potential as a neuroprotective agent for treating prenatal stress-related disorders.

[18F]FDG-PET and [18F]MPPF-PET are brain biomarkers for the creatine transporter Slc6a8 loss of function mutation

Pathogenic variants in the creatine transporter gene SLC6A8, reported to represent 2% of all intellectual disabilities in males, result in a spectrum of behavioral abnormalities including developmental delay, intellectual disability, and deficit in speech. While at present there are no effective treatments available, preclinical development and testing of gene therapy and other approaches to increase brain creatine are being actively pursued. In studying a mouse model of the disorder, [18F]fluorodeoxyglucose ([18F]FDG)-based positron emission tomography (PET)/computed tomography (CT) was performed to assess brain glucose metabolism in wild type and creatine transporter mutant mice (Slc6a8-/y). The findings demonstrate marked differences in glucose metabolism in the brains of wild type and Slc6a8-/y mice. In conducting behavioral phenotyping studies, notable abnormalities in behavior in the murine model led to additional studies in serotonin-mediated activity. Serotonergic signaling differences were detected between wild type and Slc6a8-/y mice using 4-(2'-methoxyphenyl)-1-[2'-(N-2″-pyridinyl)-p-[18F]fluorobenzamido]ethylpiperazine ([18F]MPPF). These data demonstrate that [18F]FDG-PET and [18F]-MPPF-PET may serve as appropriate and sensitive biomarkers that could be used to assess the efficacy of not only new approaches in treating mutations of the creatine transporter SLC6A8 and their effectiveness in normalizing brain metabolism but also in enhancing our understanding of the mechanism of brain dysfunction that occurs in this complex brain disorder.

Anti-RGMa neutralizing antibody ameliorates vascular cognitive impairment in mice

Repulsive Guidance Molecule A (RGMa) is well-recognized for its role in axon guidance. Recent studies have unveiled its diverse functions under pathological conditions within the central nervous system, such as spinal cord injury, multiple sclerosis, and Parkinson's disease. In this study, we explored the involvement of RGMa and the therapeutic effects of an anti-RGMa neutralizing antibody in a mouse model of vascular dementia (VaD). The VaD mouse model was established using the bilateral common carotid artery stenosis (BCAS) method. Immunohistochemical analysis revealed that these mice exhibited increased RGMa expression in the hippocampus, which coincided with reduced neurogenesis and impaired cholinergic innervation. These alterations manifested as cognitive impairments in the BCAS mice. Significantly, treatment with anti-RGMa neutralizing antibody reversed these pathological changes and cognitive deficits. Our findings suggest that RGMa plays a pivotal role in VaD pathology within the hippocampus and propose the anti-RGMa antibody as a promising therapeutic avenue for treating VaD.

Microglia-Mediated Synaptic Dysfunction Contributes to Chemotherapy-Related Cognitive Impairment

Chemotherapy-related cognitive impairment (CRCI) significantly impacts cancer survivors. Due to unclear mechanisms, effective treatments for cognitive deficits are lacking. Here, we examined if microglia-mediated deficits in synaptic plasticity drive CRCI. Adult male mice were treated with the chemotherapeutic drugs 5-fluorouracil and leucovorin (5-Fu/LV, intraperitoneal injection, I.P.) on Days 1, 8, and 15 at a dosage of 50 mg/kg for 5-Fu and 90 mg/kg for LV for 3 weeks. Cognitive function was assessed using a novel object recognition (NOR) test 4 weeks after completion of 5-Fu/LV treatment. Compared with vehicle treatment, 5-Fu/LV treatment reduced the preference for exploring novel objects in the NOR test. Treatment with 5-Fu/LV increased the numbers of Iba1-positive microglial and CD68-positive/Iba1-positive microglia with shortened process lengths and diminished endpoints but decreased the number of phagocytotic (≤ 1 FITC-labeled beads) Iba1-positive microglia. Furthermore, 5-Fu/LV treatment reduced the long-term potentiation (LTP) recorded in the hippocampal CA1 region in response to a theta burst stimulation of the CA3-CA1 pathway and decreased the evoked N-methyl-D-aspartic acid receptor (NMDAR)-excitatory postsynaptic currents (NMDAR-EPSCs) in CA1 neurons. Cotreatment with the microglial inhibitor minocycline (33 mg/kg, daily for 3 weeks) restored cognitive deficits and microglial ramification, decreased the number of CD68-positive microglia, and reversed the reductions in LTP and the amplitude of NMDAR-EPSCs in 5-Fu/LV-treated mice. Our data suggest that microglial dysfunction and related synaptic dysfunction contribute to 5-Fu/LV-induced cognitive impairment.

Nmnat2 deficiency in the arcuate nucleus or paraventricular nucleus induces Sarm1-independent neuron loss and liraglutide-reversible obesity

Nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2) plays an important role in maintaining axon integrity, and the arcuate nucleus (ARC), and paraventricular nucleus (PVN) are crucial nuclei in the control of energy balance. However, the effect of Nmnat2 deficiency in ARC and PVN is still unclear. Nmnat2 loxP/loxP or Nmnat2 loxP/loxP , Sarm1 -/- mice were bilaterally injected with AAV-CMV-GFP-Cre once into the ARC, PVN, or lateral parabrachial nucleus (LPBN) to obtain Nmnat2 ARC-/- , Nmnat2 PVN-/- , Nmnat2 LPBN-/- , Nmnat2 ARC-/- , SKO, Nmnat2 PVN-/- , SKO, or Nmnat2 LPBN-/- , SKO mice. Syn1-Cre mice were bilaterally injected with AAV-EF1a-flex-taCasp3-TEVp once into the ARC or PVN to specifically induce neuron loss. Metabolic changes were measured in the mice intraperitoneally injected with or without liraglutide, a glucagon-like peptide-1 (GLP-1) analog. Neuron loss and neuron activation were monitored by immunofluorescence. Deletion of Nmnat2 in ARC or PVN of mice leads to neuron loss, increased food intake, and obesity in a Sarm1-independent manner. Intraperitoneal injection of liraglutide activates neurons in PVN and LPBN, and attenuates hyperphagia and obesity induced by Nmnat2 deletion or apoptosis of Syn1-positive neurons in ARC or PVN, but has no significant effect on neuron loss. Nmnat2 deficiency in LPBN leads to death within 2 weeks, which can be markedly rescued by Sarm1 deficiency. These data show that deletion of Nmnat2 in ARC or PVN in adult mice leads to Sarm1-independent neuron loss, and liraglutide-reversible hyperphagia and obesity. These findings also elucidate the integrated role of ARC or PVN for downregulating food intake, the requirement of LPBN for survival, and the ARC- or PVN-independent effect of GLP-1 on food intake.

Age-Related Differences in Lipopolysaccharide-Induced Delirium-like Behavior Implicate the Distinct Microglial Composition in the Hippocampus

As the global population ages, the mechanisms underlying age-related susceptibility to delirium have attracted attention. Given the central role of microglia in the pathogenesis of inflammation-related delirium, we investigated the temporal dynamics of neurobehavioral changes and microglial responses, following lipopolysaccharide (LPS, 200 μg/kg) administration in young and old male C57BL/6 mice. Although a similar illness trajectory across 48 h post-treatment (HPT) was observed in both age groups, old-LPS mice exhibited worsened delirium-like behavior. At 48 HPT, in old but not young mice, significantly decreased hippocampal neuronal activity coincided with microglial overactivation. Widespread hippocampal microglial activation was present at 3 HPT but subsided by 12 HPT in young but not old mice, indicating a generally retarded but prolonged microglial response to LPS challenge in old mice. However, for both age groups, at 3 HPT, p16INK4a-negative microglia (with low abundance in the aged brain) exhibited comparable morphological activation, which was not observed for p16INK4a-positive microglia (highly abundant in the aged brain). These results suggest that age-related susceptibility to LPS-induced delirium-like behavior accompanied by different patterns of microglial response might implicate microglial composition shifts and that optimizing microglial composition represents a promising approach to reduce vulnerability to inflammatory challenge.

25-Hydroxycholesterol modulates microglial function and exacerbates Alzheimer's disease pathology: mechanistic insights and therapeutic potential of cholesterol esterification inhibition

This study investigates the role of 25-hydroxycholesterol (25HC), a metabolite produced by cholesterol hydroxylase encoded by the Ch25h gene, in modulating microglial function and its potential implications in Alzheimer's disease (AD) pathology. We demonstrated that 25HC impairs microglial surveillance, reduces phagocytic capacity, and increases the production of pro-inflammatory cytokines. In vivo two-photon microscopy revealed that 25HC administration diminishes microglial response to brain lesions, while flow cytometry confirmed reduced phagocytosis in both in vivo and in vitro models. Additionally, amyloid-beta (Aβ) was shown to upregulate Ch25h expression and elevate 25HC levels in microglia, exacerbating these functional impairments. Mechanistically, 25HC was found to enhance cholesterol esterification, disrupt cell membrane dynamics, and further reduce microglial mobility and phagocytosis. Treatment with Avasimibe, a cholesterol esterification inhibitor, restored membrane dynamics and microglial function, leading to attenuated AD pathology in a 5XFAD mouse model. These findings suggest that 25HC-induced changes in microglial function contribute to AD progression, and targeting cholesterol metabolism could offer therapeutic potential.

Technical Assessment of Motor and Behavioral Tests in Rodent Models of Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a neurodegenerative disorder characterized by progressive motor and cognitive impairments, affecting millions worldwide. It significantly reduces patients' quality of life and imposes a burden on health systems. Despite advances in understanding MS, there is no cure, highlighting the need for effective therapeutic strategies. Preclinical animal models are critical for gaining insights into MS pathophysiology and treatments. However, these models fail to fully replicate the complexity of human MS, making it essential to choose appropriate models and behavioral tests to evaluate their efficacy.

PURPOSE

This review examines various motor and cognitive behavioral tests used in preclinical MS models, discussing their strengths and limitations. The goal is to guide researchers in selecting the most appropriate tests for their models, while providing insights into how these tests are performed and analyzed.

METHODS

We reviewed motor and cognitive behavioral tests used in MS models, detailing test procedures and evaluating their advantages and disadvantages.

RESULTS

This review offers a comprehensive overview that aids researchers in choosing the most suitable tests for their studies, improving the accuracy and reliability of preclinical MS research.

CONCLUSIONS

Understanding the strengths and limitations of these tests is crucial for making informed decisions, leading to better experimental designs and, ultimately, more effective therapeutic interventions for MS.