Water Maze Test Research Articles

Transgenerational Impacts of Oxidative Damage Induced by Prenatal Ethanol Exposure on Spatial Learning/Memory and BDNF in the Hippocampus of Male Rats

Alcohol consumption during pregnancy harms fetal development, leading to various physical and behavioral issues. This study investigates how prenatal ethanol exposure triggers oxidative stress (OS) and affects neurotrophic factors (NTFs), particularly brain-derived growth factor (BDNF) gene expression in the hippocampus, influencing learning and memory decline across two generations of male offspring from ethanol-exposed female rats. A rat model of fetal alcohol spectrum disorder (FASD) was initially generated to reflect on the deficits in the first generation, and then those transmitted via the male germline to the unexposed male ones. The pregnant rats were thus divided into four groups, namely, the control group (CTRL) receiving only distilled water (DW), and three groups being exposed to ethanol (20 %, 4.5 g/kg) by oral gavage, during the first 10-day gestation (FG), the second 10-day gestation (SG), and the entire gestation (EG) periods. Subsequent Morris water maze (MWM) tests on male offspring revealed spatial learning deficits during the second and entire gestational periods in both generations. Analysis of antioxidant enzyme activity including glutathione peroxidase (GPx), superoxide dismutase (SOD), and malondialdehyde (MDA), and BDNF gene expression in the hippocampus further highlighted the impacts of prenatal ethanol exposure. The study results demonstrated that prenatal ethanol exposure caused spatial learning/memory deficits during the SG and EG, altered antioxidant enzyme activity, and reduced BDNF gene expression in both generations. The findings underscore the role of OS in developmental and behavioral issues in FASD rat models and suggest that lasting transgenerational effects in the second generation may stem from alcohol-induced changes.

Wogonin mitigates microglia-mediated synaptic over-pruning and cognitive impairment following epilepsy

BackgroundEpilepsy, a neurological disorder characterized by recurrent abnormal neuronal discharges, leading to brain dysfunction and imposing significant psychological and economic burdens on patients. Microglia, the resident immune cells within the central nervous system (CNS), play a crucial role in maintaining CNS homeostasis. However, activated microglia can excessively prune synapses, exacerbating neuronal damage and cognitive dysfunction following epilepsy. Wogonin, a flavonoid from Scutellaria Baicalensis, has known neuroprotective effects via anti-inflammatory and antioxidative mechanisms, but its impact on microglial activation and synaptic pruning in neurons post-epilepsy remains unclear. MethodsSynaptic density was assessed using presynaptic marker Synaptophysin and postsynaptic marker Psd-95, and microglial phagocytosis was evaluated with fluorescent microspheres. Pilocarpine-induced mouse model of status epilepticus was used to evaluate synaptic density changes of mouse hippocampus following an intraperitoneal injection of wogonin (50 and 100 mg/kg). Memory and cognitive function in mice were subsequently evaluated using the Y-maze, object recognition, and Morris water maze tests. Single-cell sequencing was employed to investigate the underlying causes of microglial state alterations, followed by experimental validation. ResultsMicroglia were transitioned to an activated state post-epilepsy, exhibiting significantly enhanced phagocytic capacity. Correspondingly, levels of synaptophysin and Psd-95 were markedly reduced in neurons. Treatment with wogonin (100 mg/kg) significantly increased neuronal synaptic density and improved learning and memory deficits in epileptic mice. Further investigation revealed that wogonin inhibits the release of pro-inflammatory cytokines and synaptic phagocytosis of microglia by activating the AKT/FoxO1 pathway. ConclusionsWogonin could alleviate excessive synaptic pruning of epileptic neurons by microglia and improve cognitive dysfunction of epileptic mice via the AKT/FoxO1 pathway.

Gastrodin reduces Aβ brain levels in an Alzheimer's disease mouse model by inhibiting P-glycoprotein ubiquitination

BackgroundStudies have demonstrated the potential of gastrodin in the treatment of Alzheimer's disease (AD), however, its mechanism of action remains elusive. Currently, the Amyloid-β (Aβ) cascade hypothesis continues to be the prevailing theory regarding AD etiology. The ubiquitination of P-glycoprotein (P-gp) at the blood-brain barrier (BBB) contributes to the accumulation of Aβ in the brain during AD. PurposeTo investigate the mechanism of gastrodin intervention in AD. MethodsThe molecular docking, molecular dynamics simulations, and microscale thermophoresis (MST) were employed to identify the action target of gastrodin. The western blot (WB) was performed to detect the protein expression level, the ubiquitination level of P-gp was determined using co-immunoprecipitation (CO-IP) assay. P-gp transport activity was detected using an NBD-CSA fluorescence assay. Trans-Epithelial Electrical Resistance (TEER) was used to detect cell resistance. Fluorescein-labeled dextran experiments were performed to determine the individual cell permeability. The immunofluorescence (IF) was employed to detect Aβ deposition, the Morris Water Maze test was used to assess behavioral changes in APP/PS1 mice and the levels of Aβ40 and Aβ42 expression were quantified using enzyme-linked immunosorbent assay. ResultsThe FBXO15 was the target of gastrodin-mediated inhibition of P-gp ubiquitination. Gastrodin increased the P-gp expression, cell resistance, and P-gp transport activity of BEND.3 cells upon treatment with Aβ40 through mechanisms involving the reduction of FBXO15 and P-gp binding and the inhibition of P-gp ubiquitination. And gastrodin could effectively improve memory function and increase number of neurons in APP/PS1 mice, reduce the accumulation of Aβ40 and Aβ42, and enhance P-gp expression in a dose-dependent manner. ConclusionAβ40 induces the ubiquitination and proteasomal degradation of BBB P-gp, however, gastrodin inhibits the ubiquitination of P-gp by binding to FBXO15, thereby increasing P-gp protein expression and enhancing its transport function.

Long-term aerobic exercise improves learning memory capacity and effects on oxidative stress levels and Keap1/Nrf2/GPX4 pathway in the hippocampus of APP/PS1 mice

ObjectiveTo examine the effects of long-term aerobic exercise on oxidative stress and learning memory ability of APP/PS1 mice, focusing on the hippocampal Keap1, Nrf2, HO-1, and GPX4 proteins.MethodsThirty APP/PS1 double transgenic AD mice were randomly divided into three groups: model group, short-term exercise group, and long-term exercise group, with 10 mice in each group. Male non-transgenic mice of the same age served as the control group. The groups underwent swimming training for 6 weeks and 12 weeks, respectively. After the intervention, cognitive abilities were assessed using the Morris water maze test. Hippocampal tissue samples were analyzed for changes in superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. ROS expression was observed using dihydroethidium probe, and Keap1, Nrf2, HO-1, and GPX4 protein levels were detected by Western blot analysis.ResultsAerobic exercise significantly reduced the escape latency and increased both the time spent in the target quadrant and the number crossing the platform compared to the model group (p < 0.05). In the hippocampus, aerobic exercise significantly reduced the MDA content, while significantly increased SOD activity (p < 0.05). The level of ROS in the hippocampal region was significantly reduced by aerobic exercise (p < 0.05), with decreased Keap1 protein expression of and increased Nrf2, HO-1, GPX4 protein expression (p < 0.05).ConclusionAerobic exercise enhances memory and learning abilities, improves cognitive function, and reduces the oxidative stress levels in the hippocampus of AD mice, which involves in the activation of Keap1/Nrf2/GPX4 pathway.

Effect and mechanism of Donepezil hydrochloride on Alzheimer’s disease

Objective: To explore the effect and mechanism of donepezil hydrochloride on Alzheimer’s disease (AD).Methods: Thirty-six 3-month-old SD rats were selected as the research subjects and randomly divided into a normal control (NC) group and a model group. The model group was given continuous intraperitoneal injection of D-galactose solution (120 mg/kg/d) combined with aluminum trichloride (10 mg/kg/d) by gavage for 60 days. Morris water maze test was conducted to test the learning and memory abilities of the rats, and AD rats were selected. After modeling, AD rats were divided into a normal saline (NS) group and a drug treatment (DT) group. The DT group was given donepezil hydrochloride (1.0 mg/kg) by gavage intervention, and the NC group and the NS group were given equal volumes of physiological saline by gavage. After 4 weeks of intervention, Morris water maze test was conducted to detect the escape latency, the number of platform crossings and residence time in the target quadrant, the rats were euthanized, with serum and hippocampal tissues collected, and hippocampal tissue homogenate (10%) was prepared by using NS. Enzyme linked immunosorbent assay (ELISA) was used to detect the inflammatory and oxidative stress indicators in rat hippocampal tissues and serum, and hematoxylin eosin (HE) staining was used to observe pathological damage in rat hippocampal tissues.Results: Compared with the NC group, the NS group showed a significant increase in escape latency (p < .05), a significant decrease in the number of platform crossings and residence time in the target quadrant (p < .05), and a significant decrease in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum and hippocampal tissues (p < .05). The content of malondialdehyde (MDA) was significantly increased (p < .05), and the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were significantly increased (p < .05). Compared with the NS group, the DT group can significantly reduce the escape latency (p < .05), increase the number of platform crossings and residence time in the target quadrant (p < .05), significantly increase the activities of SOD and GSH-Px in serum and hippocampal tissues and reduce the content of MDA (p < .05) and the levels of IL-6 and TNF-α (p < .05). After intervention with donepezil hydrochloride, the number of neurons in the hippocampus were significantly increased.Conclusions: Donepezil hydrochloride can improve the learning and memory abilities of rats, reduce the levels of oxidative stress and inflammation in the brain and serum, and improve pathological damage in the hippocampus.

Ginsenoside Rb1 ameliorates hippocampal neuroinflammation in rats after intracerebral hemorrhage by inactivating the TLR4/NF-kB pathway.

This work elucidated the therapeutic effect and mechanism of ginsenoside Rb1 on intracerebral hemorrhage (ICH). ICH rat models were treated by ginsenoside Rb1. Modified neurological deficit score, and Y-maze and Morris water-maze tests were performed on rats. Hippocampal neuronal damage was observed by Nissl staining. Rat primary astrocytes were exposed to ginsenoside Rb1, Hemin, and lipopolysaccharide (LPS). TNF-α, IL-1β, and IL-6 levels were assessed via enzyme-linked immunosorbent assay. TLR4/NF-kB pathway activity was appraised by Western blot. Immunofluorescence staining was for hippocampal glial fibrillary acidic protein (GFAP) expression and P65 protein location in hippocampus and astrocytes. In rats after ICH, ginsenoside Rb1 ameliorated neurological impairment and hippocampal neuronal damage; improved learning and memory ability; reduced brain water content; decreasedhippocampal TNF-α, IL-1β, and IL-6; inactivated TLR4/NF-kB pathway; and declined hippocampal GFAP expression. In rat primary astrocytes exposed to Hemin, ginsenoside Rb1 declined TNF-α, IL-1β, and IL-6; inactivated TLR4/NF-kB pathway; and hindered P65 protein entry into nucleus. However, these functions of ginsenoside Rb1 on the Hemin-induced astrocytes were abolished by LPS. Ginsenoside Rb1 has promising future for clinical ICH treatment, which exerts therapeutic effect on ICH by ameliorating hippocampal neuroinflammation via inactivating the TLR4/NF-kB pathway.

Protective effects of geraniol in a male rat model of Alzheimer's disease: A behavioral, biochemical, and histological study.

Alzheimer's disease (AD) as a neurodegenerative disease can cause behavioral impairments due to oxidative stress. Aging and oxidative conditions are some AD risk factors. We assessed the influence of geraniol (GR), an acyclic monoterpene alcohol, on behavioral functions, hippocampal oxidative status, and histological alterations in AD rats induced by amyloid-β (Aβ). Male Wistar rats (n = 70) were randomly allocated to the control, sham, AD, control-GR (100 mg/kg; per oral: P.O.), AD-GR (100 mg/kg; P.O.; treatment), GR-AD (100 mg/kg; P.O.; pretreatment), and GR-AD-GR (100 mg/kg; P.O.; pretreatment + treatment) groups. GR administration was done for four continuous weeks. After treatments, novel object recognition (NOR) and Morris water maze (MWM) tests assessed the animals' behavior. Then, hippocampal specimens were collected for biochemical assessment. Finally, the number of intact neurons was identified in the hippocampus using hematoxylin and eosin staining. Aβ microinjection increased learning and memory deficits in both NOR and MWM tests, oxidative stress status, and neuronal loss. Oral GR administration improved behavioral deficits and reduced oxidative stress status and neuronal loss in the Aβ-infused animals. GR ameliorates behavioral impairments through a decrease in neuronal degeneration and oxidative stress.

Effect of electroacupuncture on synaptic ultrastructure and synaptic function related proteins PSD95 and MeCP2 in sleep deprivation rats

To observe the effect of electroacupuncture (EA) on the expression of synaptic function related proteins PSD95 and MeCP2 and synaptic ultrastructure in sleep deprived rats, so as to explore its mechanism underlying improvement of learning and memory ability caused by sleep deprivation. SD rats were randomly divided into normal, model, EA and sham EA groups (n=10). The sleep deprivation model was prepared by modified multi-platform water environment. Rats of the EA group received EA stimulation at "Baihui" (GV20) and "Dazhui" (GV14), while the sham EA group received shallow needling 4 mm away from the above acupoints without electrical stimulation. The learning and memory ability was evaluated with Morris water maze test. The density of dendritic spines in hippocampal CA1 region was detected by Golgi staining. The synaptic ultrastructure of hippocampus was observed by electron microscope. The protein expression levels of PSD95 and MeCP2 in hippocampus was detected by Western blot. Compared with the normal group, the escaping latency of the positioning navigation experiment in the model group was prolonged (P<0.05), the number of crossing the platform and the residence time in the target quadrant were decreased(P<0.05), the density of dendritic spines in the hippocampal CA1 area was decreased (P<0.05), the number of synapses was reduced, with swollen synaptosomes, blurred synaptic structure, disappeared and narrowed synaptic clefts, the protein expression levels of PSD95 and MeCP2 were significantly decreased (P<0.05) in the model group. Compared with the model group, the escape latency of the positioning navigation experiment was shortened (P<0.05), the number of crossing platforms and the time spent in the target quadrant were increased (P<0.05), the density of dendritic spines in the hippocampal CA1 region was increased (P<0.05), the morphology of synaptic improved, the protein expression levels of PSD95 and MeCP2 were increased (P<0.01) in the EA and sham EA groups. The improvement of the above indexes in EA group was more obvious than those in sham EA group. EA can improve the learning and memory of sleep deprivation rats, which may be related to its function in regulating the expressions of synaptic related proteins PSD95 and MeCP2, and improving the synaptic structure.

Ganglioside GM1 Alleviates Propofol-Induced Pyroptosis in the Hippocampus of Developing Rats via the PI3K/AKT/NF-κB Signaling Cascade

In pediatric and intensive care units, propofol is widely used for general anesthesia and sedation procedures as a short-acting anesthetic. Multiple studies have revealed that propofol causes hippocampal injury and cognitive dysfunction in developing animals. As is known, GM1, a type of ganglioside, plays a crucial role in promoting nervous system development. Consequently, this study explored whether GM1 mitigated neurological injury caused by propofol during developmental stages and investigated its underlying mechanisms. Seven-day-old SD rats or PC12 cells were used in this study for histopathological analyses, a Morris water maze test, a lactate dehydrogenase release assay, Western blotting, and an ELISA. Furthermore, LY294002 was employed to explore the potential neuroprotective effect of GM1 via the PI3K/AKT signaling cascade. The results indicated that GM1 exerted a protective effect against hippocampal morphological damage and pyroptosis as well as behavioral abnormalities following propofol exposure by increasing p-PI3K and p-AKT expression while decreasing p-p65 expression in developing rats. Nevertheless, the inhibitor LY294002, which targets the PI3K/AKT cascade, attenuated the beneficial effects of GM1. Our study provides evidence that GM1 confers neuroprotection and attenuates propofol-induced developmental neurotoxicity, potentially involving the PI3K/AKT/NF-κB signaling cascade.

Mechanism of Pyroptosis in Postoperative Cognitive Dysfunction Rats and α7-nicotinic Receptor Agonist Regulating NLRP3 Inflammasome Activation

Background: This study investigates the efficacy of α7-nicotinic acetylcholine receptor (α7nAChR) agonists in mitigating postoperative cognitive dysfunction (POCD) in a rat model. This investigation aimed to elucidate the therapeutic potential of α7nAChR agonists in modulating neuroinflammatory pathways to improve cognitive outcomes post-surgery. Objective: Serum levels of pro-inflammatory cytokines IL-1β and IL-18 were measured as markers of systemic inflammation, while the expression levels of NLRP3 mRNA were quantified to evaluate pyroptosis and NLRP3 inflammasome activation. Methods: Adult male Sprague-Dawley rats were divided into control (no surgery), POCD (surgeryinduced), and POCD treated with an α7nAChR agonist. Cognitive function was assessed using the Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests. Results: The results showed a notable cognitive impairment in the group with POCD, as shown by increased escape latency noted in the MWM test and decreased discrimination index in the NOR test, while controls had no change. However, treatment with the α7nAChR agonist led to a significant improvement in cognitive performance among the POCD rats such that it closely matched those of the controls. Furthermore, the POCD group exhibited elevated serum levels of IL-1β and IL-18 and increased expression of pyroptosis-related markers, indicating enhanced neuroinflammation and inflammasome activation. Conclusion: These findings highlighted the therapeutic efficacy of α7nAChR agonists in mitigating neuroinflammation and improving cognitive outcomes post-surgery. Our study supports the potential of targeting the cholinergic anti-inflammatory pathway, emphasizing clinical evaluation of α7nAChR agonists in postoperative patients.

Effects of Black Rice Anthocyanin Extract on Depression-Like Behavior in Chronic Unpredictable Mild Stress Model Mice

Objective: To investigate the effects of black rice anthocyanins extract (BSE) on depression-like behavior in mice with chronic unpredictable mild stress (CUMS). Methods: A total of 30 male Kunming mice were randomly divided into Control group, model group (CUMS) and black rice anthocyanin extract group (300 mg/kg). Except the blank group, all mice were treated with CUMS to induce depression. After 21 days of intragastric administration, the behavioral changes of the mice were analyzed by body weight, sucrose preference test, open field test, and water maze test. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT). Hematoxylin-eosin staining (HE) was used to observe the pathological changes of neurons in hippocampal CA1 and CA3 regions. Cell apoptosis in hippocampus was detected by terminal deoxynucleotidyl transferase-mediated dutP Nick end labeling (TUNEL) staining. Results: Compared with the model group, the brown-rice anthocyanin treatment group showed significantly increased sucrose preference, increased horizontal movement distance and vertical standing times in the open field test, decreased escape latency in the water maze test, increased residence time in the target quadrant and the number of crossing the platform, and alleviated the damage of hippocampal neurons. Plasma ACTH, CORT, and CRH levels were decreased, and apoptosis rates in the hippocampus were decreased. Conclusion: Black rice anthocyanins have a significant antidepressant effect possibly by regulating the function of HPA axis.

Nucleus accumbens shell electrical lesion attenuates seizures and gliosis in chronic temporal lobe epilepsy rats.

Temporal lobe epilepsy (TLE) is the most prevalent form of epilepsy. Prior research has indicated the involvement of the nucleus accumbens shell (NAcSh) in the process of epileptogenesis, thereby implying its potential as a therapeutic target for TLE. In the present study, we investigated the antiepileptic effect of the NAcSh electrical lesion. Chronic TLE was induced by stereotactic injection of kainic acid (KA) into the hippocampus 3 weeks after KA administration, and NAcSh electrical lesions were performed. Seizures in rats were monitored by video electroencephalogram (EEG) 1 week following the NAcSh electrical lesion. Besides, the spatial memory function assessment in rats was conducted using the Morris water maze (MWM) test in the final week of the experiment. Later, hippocampal glial cell activation and neuron loss in rats were evaluated through immunohistochemistry. TLE rats subjected to NAcSh electrical lesion exhibited a significant reduction in the frequency of seizures compared to untreated TLE rats. Furthermore, NAcSh electrical lesion led to less activation of hippocampal glial cells and fewer neuronal loss in TLE rats. It is worth noting that the NAcSh electrical lesion did not cause additional memory impairment. In the present study, the NAcSh electrical lesion exhibited a definitive therapeutic effect on the chronic TLE rat model, potentially due to decreased hippocampal TLE-induced activation of glial cells and neuron loss. In conclusion, our results indicated that the NAcSh is a promising therapeutic target for TLE and possesses high potential for clinical application.

Dopamine agonist Rotigotine mitigates lipopolysaccharide-induced neuroinflammation and memory impairment in mice.

Dopaminergic signaling in the Central Nervous System (CNS) has been observed in the pathophysiology of memory deficits. Rotigotine belongs to a non-ergot-based dopamine receptor agonist possessing anti-inflammatory properties. However, it is uncertain if it has a role in ameliorating cognitive decline. Here, we evaluated the actions of rotigotine on neuroinflammation and memory impairment. Rotigotine 1, 3, and 5mg/kg were administered to mice subcutaneously once a day for fifteen days. Lipopolysaccharide (LPS) 750µg/kg was administered intraperitoneally for seven days to produce cognitive impairment in mice. Morris water maze and Passive avoidance step-down tests were performed to evaluate memory function. Further, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and amyloid-beta (Aβ) were estimated by ELISA. The mouse brain was analyzed for acetylcholinesterase (AChE) activity, lipid peroxidation, catalase, and reduced glutathione levels. LPS elevated IL-6, Aβ, TNF-α, and AChE activity, promoted oxidative stress, and caused memory decline in mice. Lower doses of rotigotine 1 and 3mg/kg significantly reduced neuroinflammation, oxidative stress, and AChE activity, followed by improved cognitive impairment. Our data suggest that rotigotine 1 and 3mg/kg could reverse the neuroinflammation-associated memory impairment.

NEK7 induces lactylation in Alzheimer's disease to promote pyroptosis in BV-2 cells.

Alzheimer's disease (AD), an age-related neurodegenerative disorder, is characterized by irreversible brain tissue degeneration. The amyloid-β (Aβ) cascade hypothesis stands as the predominant paradigm explaining AD pathogenesis. This study aimed to elucidate the mechanisms underlying Aβ-induced pyroptosis in AD. AD models were established using amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice and Aβ-treated BV-2 cells (5 µM, 24h). NEK7 expression was evaluated in vitro and in vivo. Cell pyroptosis was assessed before and after NEK7 expression was inhibited in BV-2 cells. Adeno-associated virus (AAV) vectors carrying short hairpin RNA (shRNA) against NEK7 (AAV-sh-NEK7) were administered to mice to knockdown NEK7 in vivo. Spatial learning and memory abilities were evaluated using the Morris water maze test. The interaction between NEK7 and histone H4 lysine 12 lactylation (H4K12la) were then investigated. The results suggested that NEK7 expression was markedly elevated in both in vitro and in vivo AD models. Treatment with Aβ significantly reduced cell viability and enhanced pyroptosis in BV-2 cells; these effects were reversed by inhibiting NEK7. Furthermore, AD mice with NEK7 knockdown exhibited shorter escape latencies and increased time spent in the target quadrant, suggesting that NEK7 inhibition improved cognitive function and memory retention. Mechanistically, Aβ treatment induced histone lactylation in BV-2 cells, and suppression of lactylation attenuated NEK7 transcriptional activity and mRNA levels. In summary, elevated NEK7 expression promoted histone lactylation in BV-2 cells, thereby facilitating pyroptosis. Inhibition of NEK7 conferred protection against Aβ-induced cellular damage and enhanced cognitive performance and memory retention in AD model mice. Collectively, targeting NEK7 represents a potential therapeutic strategy for alleviating AD symptoms.

Flaxseed Oil: Safeguarding Neurological Health through Apoptosis and Oxidative Damage Defense

: The present study aims to investigate the neuroprotective properties of flaxseed oil (FSO) in reducing cadmium-induced neurotoxicity. The neuroprotective properties of FSO were observed in rats by examining the expression of caspase-3 and Bcl-2 to determine the antiapoptotic capabilities of FSO. Methods: Rats were given cadmium orally at a dosage of 5 mg/kg/day for 30 days, along with flaxseed oil (FSO) at doses of 2ml/kg/day and 3ml/kg/day for the same duration. The Morris watermaze test (MWM) and the Novel object recognition test (NOR) were performed to evaluate learning and memory abilities. We quantified the amounts of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), and acetylcholinesterase inhibitory activity (AChE) in the entire brain homogenate. Additionally, apoptosis and histopathology studies were conducted on rat brain tissues. Results: Intoxication with cadmium was associated with significant impairment of learning and memory in Morris watermaze (MWM) and novel object recognition (NOR) tests. The group that consumed Cd showed elevated levels of MDA, NO, and AChE in the brain homogenate, higher levels of caspase-3 and Bcl-2, and decreased levels of GSH compared to the control group. Animals treated with FSO exhibited improved learning and memory function, along with balanced levels of oxidative and cholinergic activity in brain tissue. Additionally, levels of caspase-3 and Bcl-2 were reduced in a similar way to the control group. Conclusions: The study demonstrates that flaxseed oil has positive effects by raising GSH and antiapoptotic potential levels while reducing MDA, NO, and AChE levels in the brain. This contributes to neuroprotection and decreases neuronal death, as supported by histopathological findings.

Activation of Hippocampal Neuronal NADPH Oxidase NOX2 Promotes Depressive-Like Behaviour and Cognition Deficits in Chronic Restraint Stress Mouse Model.

Nicotinamide adenosine dinucleotide phosphate oxidases (NOX) play important roles in mediating stress-induced depression. Three NOX isotypes are expressed mainly in the brain: NOX2, NOX3 and NOX4. In this study, the expression and cellular sources of these NOX isoforms was investigated in the context of stress-induced depression. Chronic restraint stress (CRS)-induced depressive-like behaviour and cognitive deficits were evaluated by tail suspension tests, forced swimming tests and the Morris water maze test. Hippocampal NOX expression was determined by immunofluorescence staining and western blotting. The hippocampal levels of the brain-derived neurotrophic factor (BDNF) mRNA were determined via quantitative real-time -polymerase chain reaction. Glucocorticoid levels in the hippocampus were measured using ELISA kits. In the mouse CRS model, a significant increase in NOX2 expression was observed in the hippocampus, whereas no significant changes in NOX3 and NOX4 expression were detected. Next, NOX2 expression was primarily localised to neurons (NeuN+) but not microglia (Iba-1+) or astrocytes (GFAP+). Treatment with gp91ds-tat, a specific NOX2 inhibitor, effectively mitigated the behavioural deficits induced by CRS. The decreased expression of the BDNF mRNA in the hippocampus of CRS mice was restored upon gp91ds-tat treatment. A positive correlation was identified between neuronal NOX2 expression and serum glucocorticoid levels. Our study indicated that neuronal NOX2 may be a critical mediator of depression-like behaviours and spatial cognitive deficits in mice subjected to CRS. Blockade of NOX2 signalling may be a promising therapeutic strategy for depression.

Cirsilineol improves anesthesia/surgery-induced postoperative cognitive dysfunction through attenuating oxidative stress and modulating microglia M1/M2 polarization.

Cirsilineol is a trimethoxy and dihydroxy flavonoid isolated from plant species such as Artemisia vestita and has a variety of pharmacological properties. This study analyzed whether cirsilineol could prevent postoperative cognitive dysfunction (POCD). A POCD mouse model induced by anesthesia/surgery induction and a cell model established with hydrogen peroxide (H2O2)-induced microglia BV-2 were employed to explore the efficacy of cirsilineol on POCD. The cognition function of the mice were assessed by carrying out behavioral tests (Morris water maze test and Y-maze test). We assessed the activation and polarization status of microglia using immunofluorescence analysis and detected the expression levels of CD86 and CD206 using the quantitative PCR (qPCR). Subsequently, cell viability was determined by CCK-8 assay and apoptosis was assessed using Calcein-AM/PI staining. Meanwhile, superoxide dismutase (SOD) and malondialdehyde (MDA) levels in plasma and cell culture medium were detected using chemiluminescence. Finally, the phosphorylation levels of JAK/STAT signaling pathway-related proteins were analyzed by Western blot. Cirsilineol reduced the escape latency and times of crossing island and increased spontaneous alternation (SA) rate, restoring the cognitive dysfunctions of POCD-modeled mice. Meanwhile, POCD elevated CD86 expression and malondialdehyde content and lowered the level of SOD; however, cirsilineol promoted CD206 expression and generation of SOD and inhibited malondialdehyde production. In H2O2-induced microglia BV-2, cirsilineol treatment increased SOD content and suppressed the generation of reactive oxygen species (ROS) and malondialdehyde, modulating microglia M1/M2 polarization and JAK/STAT pathway. Cirsilineol prevented against POCD by attenuating oxidative stress and modulating microglia M1/M2 polarization, providing novel insights for the management of POCD.

Repurposing of erythropoietin as a neuroprotective agent against methotrexate-induced neurotoxicity in rats.

Methotrexate (MTX) is a cytotoxic drug that can trigger neurotoxicity via enhancing oxidative stress, apoptosis, and inflammation. On the other hand, erythropoietin (EPO) functions as an antioxidant, anti-apoptotic, and anti-inflammatory agent, in addition to its hematopoietic effects. The present study was developed to examine the neuroprotective impact of EPO against MTX-provoked neurotoxicity in rats. Chemo fog was elicited in Wistar rats via injection of one dosage of MTX (20 mg/kg, i.p) on the sixth day of the study. EPO was injected at 500 IU/kg/day, i.p for 10 successive days. MTX triggered memory and learning impairment as evidenced by Morris water maze, passive avoidance, and Y-maze cognitive tests. In addition, MTX induced oxidative stress as evident from the decline in hippocampal Nrf2 and HO-1 levels. MTX brought about apoptosis, as demonstrated by the elevation in p53, caspase-3, and Bax levels, as well as the decrease in Bcl2 levels. MTX also decreased Beclin-1, an autophagy-related marker, and increased P62 expression. In addition, MTX downregulated Sirt-1/AKT/FoxO3a pathway and increased miRNA-34a gene expression. Moreover, MTX increased acetylcholinesterase activity and reduced neurogenesis. EPO administration remarkably counteracted MTX-induced molecular and behavioral disorders in rat hippocampi. Our findings impart preclinical indication for repurposing of EPO as a promising neuroprotective agent through modulating miRNA-34a, autophagy, and the Sirt-1/FoxO3a signaling pathway.

Exercise rescues cognitive impairment through inhibiting the fibrinogen neuroinflammative pathway in diabetes.

Fibrinogen is a pivotal factor in the activation of neuroinflammation and cognitive impairment. While exercise, especifically swimming, has demonstrated cognitive benefits, the molecular protective mechanisms orchestrated by exercise in response to blood-brain barrier (BBB) leakage in diabetes remain elusive. This study systematically investigates the impact of fibrinogen on neuroinflammation and the role of exercise in diabetic rats. Diabetic rats underwent an 8-week swimming exercise regimen, and subsequent assessments included changes in interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), astroglia activation, BBB permeability, and key epithelial tight junction proteins such as zona occludins (ZO)-1, Claudin-5, and matrix metalloproteinase-9 (MMP-9). Spatial learning and memory were evaluated using the Morris water maze test and the novel object recognition test. The study revealed that exercise significantly improved cognitive function, potentially by suppressing fibrinogen levels and astroglia activation. Intriguingly, heightened fibrinogen expression markedly attenuated the protective effects of exercise on BBB integrity. Fibrinogen emerged as a potential compromise to exercise protective effect by increasing expression levels of inflammatory factors IL-1β and TNF-α. In summary, our findings elucidate that fibrinogen may contribute to the deterioration of cognition and diminish the protective effects of exercise by amplifying the neuroinflammatory process through damaged BBB in diabetes.

Diethyl butylmalonate attenuates cognitive deficits and depression in 5×FAD mice.

Alzheimer's disease (AD), characterized by cognitive impairment and depression, is currently one of the intractable problems due to the insufficiency of intervention strategies. Diethyl butylmalonate (DBM) has recently attracted extensive interest due to its anti-inflammatory role in macrophages. However, it is still unknown whether DBM has a beneficial effect on cognitive deficits and depression. DBM was administrated to 5×FAD and C57BL/6J mice by intraperitoneal injection. Novel object recognition, Y-maze spatial memory, Morris water maze and nest building tests were used to evaluate cognitive function. Moreover, the tail suspension test, forced swimming test, open field test and the elevated plus maze test were used to assess depression. Transmission electron microscopy, Golgi-Cox staining, immunofluorescence, RT-qPCR and western blot were utilized to determine the neuropathological changes in the hippocampus and amygdala of mice. Multiple behavioral tests showed that DBM effectively mitigated cognitive deficit and depression in 5×FAD mice. Moreover, DBM significantly attenuated synaptic ultrastructure and neurite impairment in the hippocampus of 5×FAD mice, paralleled by the improvement of the deficits of PSD95 and BDNF proteins. In addition, DBM decreased the accumulation of microglia and downregulated neuroinflammation in the hippocampus and amygdala of 5×FAD mice. This study provides evidence that DBM ameliorates cognitive deficits and depression via improvement of the impairment of synaptic ultrastructure and neuroinflammation, suggesting that DBM is a potential drug candidate for treating AD-related neurodegeneration.