Maze Test Research Articles

Comparison of Malondialdehyde, Acetylcholinesterase, and Apoptosis-Related Markers in the Cortex and Hippocampus of Cognitively Dysfunctional Mice Induced by Scopolamine

Objectives: Until now, many researchers have conducted evaluations on hippocampi for analyses of cognitive dysfunction models using scopolamine. However, depending on the purposes of these analyses, there are differences in the experimental results for the hippocampi and cortexes. Therefore, this study intends to compare various analyses of cognitive dysfunction after scopolamine administration with each other in hippocampi and cortexes. Methods: Scopolamine was administered at three dosages in mice: 0.5, 1, and 3 mg/kg. And this study evaluates the differences in cognitive function and the expression of malondialdehyde (MDA), acetylcholinesterase (AChE), and brain-derived neurotrophic factor (BDNF) in mice’s hippocampi and cortexes based on scopolamine dosages. Results: The Morris water maze test was conducted between 1 and 3 h after scopolamine injection to assess its duration. A significant decrease in behavioral ability was evaluated at 1 h, and we observed a similar recovery to the normal group at 3 h. And the Morris water maze escape latency showed differences depending on scopolamine concentration. While the escape waiting time in the control group and scop 0.5 administration group remained similar to that seen before administration, the administration of scop 1 and 3 increased it. In the experimental group administered scop 1 and 3, cerebral MDA levels in the cerebral cortex significantly increased. In the hippocampus, the MDA level in the scopolamine-administered groups slightly increased compared to the cortex. A Western blotting assay shows that Bax and Bcl-xl showed a tendency to increase or decrease depending on the concentration, but BDNF increased in scop 0.5, and scop 1 and 3 did not show a significant decrease compared to the control at the cerebral cortex. In the hippocampus, BDNF showed a concentration-dependent decrease in expression. Conclusions: This study’s findings indicate that chemical analyses for MDA and AChE can be performed in the cerebral cortex, while the hippocampus is better suited for protein analysis of apoptosis and BDNF.

Dihydro-resveratrol ameliorates NLRP3 inflammasome-mediated neuroinflammation via Bnip3-dependent mitophagy in Alzheimer's disease.

Dihydro-resveratrol (DHR), a polyphenol derivative, that has been demonstrated to suppress inflammation-mediated injury. However, it is still unknown whether it has anti-neuroinflammatory and neuroprotective effects, and a therapeutic action in Alzheimer's disease (AD). The anti-inflammatory and anti-Alzheimer's disease actions of dihydro-resveratrol were investigated using lipopolysaccharide (LPS) and AD mice models, and primary microglial cells. The changes in behaviour in mice were detected by the Morris water maze test and open-field test. Flow cytometry assay, western blotting, immunofluorescence assays and co-immunoprecipitation were used to investigate the changes in the NLRP3 inflammasome activation and mitophagy. In this study, in vivo observations indicated that the administration of dihydro-resveratrol (DHR) dramatically restored spatial learning, memory ability, autophagy and mitophagy, attenuated NLRP3 inflammasome activation, neuroinflammation and amyloid precursor protein pathology in LPS mice and AD mice. In addition, the inhibition of autophagy and mitophagy, or the activation of NLRP3 in vivo greatly abolished DHR-generated therapeutic efficacy on neuroinflammation, amyloid precursor protein pathology and cognitive loss. Further examination indicated that the application of DHR after the LPS and ATP exposure significantly inhibited the NLRP3 inflammasome activation, neuroinflammation and enhanced autophagic and mitophagic activation in microglia. Additionally, in vitro results show that DHR protects microglial cells against LPS and ATP-induced cytotoxicity by inhibiting NLRP3 inflammasome through activating Bnip3-dependent mitophagy and ULK phosphorylation. In summary, these findings suggest that dihydro-resveratrol (DHR) possesses potent anti-neuroinflammatory property and can act as a potential therapeutic agent for the treatment of AD.

Body image is associated with persistence. A study of the role of weight-related stigma.

The study replicates a preliminary report from 2019 on therelationship between body image and persistence. The aim of our study was to analyze the associations between body image, persistence, and body weight stereotypes. A total of 750 individuals were recruited for the study. The research was carried out in computer labs. The procedure consisted of psychological questionnaires (Persistence Scale, The Body Esteem Scale, Perceived Weight Stigma Questionnaire, Weight Bias Internalization Scale, Hospital Anxiety and Depression Scale, Formal Characteristics of Behavior - Temperament Inventory, and NEO-PI-R) and The Maze Test (a computer tool). After completing the Simple Maze Test, saliva samples were collected. Next, the subjects proceeded to the laboratory where anthropometric and body composition measurements were taken. The hormone levels (cortisol and dehydroepiandrosterone) in the collected saliva samples were analyzed via ELISA to determine stress. Body image and persistence are related variables. They are associated with the internalization of stereotypes and perceived stigma related to body weight. These associations are differentially shaped according to sex and the regularity of body weight. In women, a stronger association of these variables with body image was observed, while in men, the relationship with body image was weaker, with a stronger association shown by perceived weight-related stigma. In the group of participants with a BMI<18.5, there was no significant association between the internalization of stereotypes and the analyzed variables. This relationship appeared in the group of subjects with a normal body weight and was strongest in the group of participants who were overweight or obese. Perceived weight-related stigma was most strongly associated with body image in the group with BMI<18.5 kg/m2 and with persistence in the group with BMI>25 kg/m2. Body-related stigma affects not only overweight and obese individuals and its mechanisms may be shaped differently.

Electroacupuncture improves cognitive function by modulating hippocampal lactate-mediated HIF-1α signaling pathway and inhibiting inflammation response in vascular dementia rats

To observe the effects of electroacupuncture (EA) stimulation of "Sishencong"(EX-HN1) and "Fengchi"(GB20) on lactate (Lac) content, expression of proline hydroxylase 2 (PHD2), hypoxia-inducible factor-1α (HIF-1α)/nuclear transcription factor- κB (NF- κB)/NOD-like receptor thermoprotein structural domain-associated protein 3 (NLRP3) signaling pathway, and inflammatory factors in hippocampal tissue of vascular dementia (VD) rats, so as to explore its mechanisms underlying improvement of VD. Male SD rats screened by Morris water maze tests were randomly divided into blank control, sham-operation, VD model and EA groups (12 rats in each group). The VD model was replicated using the 4-vessel occlusion (VO) method. EA (2 Hz, 1 mA) was applied to EX-HN1 and bilateral GB20 for 30 min, once daily for consecutive 21 days. Morris water maze test was employed to test the rat's memory learning ability before and after modeling and after the intervention. The hippocampal tissue was sampled for observing histopathologic changes with H.E. staining；and detecting Lac content with colorimetric method, and the contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-18 (also in serum) by using ELISA, respectively. The immunoactivity levels of PHD2, HIF-1α, and p-NF-κB p65 in hippocampal tissue were detected by immunohistochemistry, and the expression levels of PHD2, HIF-1α, NF-κB p65, p-NF-κB p65 and NLRP3 proteins in hippocampal tissue were detected by Western blot. Compared with the blank control and sham-operation groups, the escaping latency, Lac content in hippocampus, the TNF-α, IL-1β, and IL-18 contents in both hippocampus and serum, the immunoactivity of HIF-1α and p-NF-κB p65 and expression levels of HIF-1α, NF-κB p65, p-NF-κB p65, and NLRP3 proteins were significantly increased (P<0.01), while the number of original platform crossing, and PHD2 immunoactivity and protein expression level were significantly decreased (P<0.05, P<0.01) in the model group. Following EA intervention, modeling induced increase and decrease of the indexes mentioned above were all reversed in the EA group (P<0.05, P<0.01). H.E. staining showed disordered arrangement of neurons, uneven cytoplasm stain, blurred nucleolus or disappearance of nucleolus, dilated capillaries, many apoptotic bodies and increased inflammatory cells in the hippocampus tissue of the model group, which was improved to a certain extent in the EA group, including relatively regular arrangement of neurons, reduced apoptotic bodies and inflammatory cells, etc. in the hippocampus. EA stimulation of EX-HN1 and GB20 can improve the cognitive function in VD rats, which may be related to its functions in reducing Lac content, regulating the expression of HIF-1α pathway related proteins, and inhibiting inflammatory responses in the hippocampus tissue.

Structure-Function Correlation in Cobalt-Induced Brain Toxicity.

Cobalt toxicity is difficult to detect and therefore often underdiagnosed. The aim of this study was to explore the pathophysiology of cobalt-induced oxidative stress in the brain and its impact on structure and function. Thirty-five wild-type C57B16 mice received intraperitoneal cobalt chloride injections: a single high dose with evaluations at 24, 48, and 72 h (n = 5, each) or daily low doses for 28 (n = 5) or 56 days (n = 15). A part of the 56-day group also received minocycline (n = 5), while 10 mice served as controls. Behavioral changes were evaluated, and cobalt levels in tissues were measured with particle-induced X-ray emission. Brain sections underwent magnetic resonance imaging (MRI), electron microscopy, and histological, immunohistochemical, and molecular analyses. High-dose cobalt caused transient illness, whereas chronic daily low-dose administration led to long-term elevations in cobalt levels accompanied by brain inflammation. Significant neurodegeneration was evidenced by demyelination, increased blood-brain barrier permeability, and mitochondrial dysfunction. Treated mice exhibited extended latency periods in the Morris water maze test and heightened anxiety in the open field test. Minocycline partially mitigated brain injury. The observed signs of neurodegeneration were dose- and time-dependent. The neurotoxicity after acute exposure was reversible, but the neurological and functional changes following chronic cobalt administration were not.

Analysis of correlations between behavioral parameters in the elevated plus maze and the levels of interleukin-1beta in blood plasma in rats

Peripheral cytokines may influence psychoemotional behavior, but the role of interleukin-1beta (IL-1beta) in altering anxiety and motor activity in response to inflammatory activation remains unclear. To clarify this issue, correlations between behavioral parameters in the elevated plus maze (EPM) test and plasma levels of IL-1beta after administration of the proinflammatory stimulus lipopolysaccharide (LPS) in different modes were analyzed in adult male rats. LPS in doses of 0.5 or 5 mg/kg, as well as physiological solution (control), were administered to rats intraperitoneally. The most pronounced behavioral effect 24 hours after a single injection was an endotoxin dose-dependent inhibition of the animals’ motor activity. After a dose of 5 mg/kg, increased anxious behavior was also noted every other day. The behavioral changes caused by the high dose of endotoxin were completely normalized after a week. The behavior of the animals one day after the end of repeated injections of LPS at a lower dose for a week (0.5 mg/kg; once every two days) also did not differ from the control. The inhibition of motor activity after LPS could be due to an increase in the level of IL-1beta in the blood plasma, as indicated by the identified significant negative correlations between IL-1beta and the corresponding behavioral parameters. No significant correlation was found between the peripheral level of IL-1beta and such a classic indicator of anxiety as the percentage of entries into the open arms of the maze. In general, the obtained results allow us to conclude that IL-1beta is an undoubted participant in the mechanism of the transient inhibitory effect of LPS on motor activity.

Effect of supplementation to offspring during early gestation and the growing phase with different sources of fatty acids on learning and memory ability of post-weaning lambs

Abstract The objective of the current experiment was to evaluate the effects of supplementation with different dietary fatty acid profiles on the dam during the first third of gestation and on the offspring during growth on the offspring’s cognitive behavior. Seventy-nine post-weaning lambs were blocked by body weight and sex using a 2×2 factorial arrangement of treatments. The first factor (maternal supplementation; MS) was supplementation to the ewes in the first third of gestation with 1.61% Ca salts of palm fatty acid distillate (PFAD) or Ca salts enriched with eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) to early pregnant ewes. The second factor (offspring supplementation; OS) was to supplement the offspring during their growing phase with diets that contained 1.48% of PFAD or Ca salts of PFAD or EPA and DHA. Ewes were housed in groups, three ewes per pen and 12 pens per treatment, with different treatments until day 50 of gestation. From day 51 of gestation until weaning, all the animals (ewes and lambs) were housed in a common pen. After weaning, lambs were housed in group pens (5 pens per treatment, three to five per pen). The lambs ran maze tests on weeks five and seven after weaning to evaluate cognitive ability. The maze contained two trap zones and had the pen conspecific lambs at the end of the maze. The measurements were the times to solve the traps and the total time to complete the maze. Data were analyzed using a mixed procedure considering the 2×2 factorial arrangement of treatments. There was a MS × OS × time interaction for the time to complete the maze (P = 0.02). Lambs receiving a different type of fatty acid supplementation during gestation than post-weaning took less time to complete the maze on the second relative to the first day compared with the lambs fed the same type of fatty acids during gestation and growing. In conclusion, combining different fatty acids during different life stages may improve lambs' cognitive abilities.

The administration of a phentolamine infusion into the basolateral amygdala enhances long-term memory and diminishes anxiety-like behavior in stressed rats.

The basolateral amygdala (BLA) contains adrenergic receptors, which are known to be involved in stress, anxiety, and memory. The objective of this study was to explore whether inhibition of α-adrenergic receptors (by phentolamine, an α-adrenergic receptor antagonist) in the BLA can reduce foot-shock stress-induced anxiety-like behavior, memory deficits, and long-term potentiation (LTP) deficits within the CA1 region of the rat hippocampus. Forty male Wistar rats were assigned to the intact, control, stress (Str), Phent (phentolamine), and Phent + Str groups. Animals were subjected to six shocks on 4 consecutive days, and phentolamine was injected into BLA 20 min before the animals were placed in the foot-shock stress apparatus. Results from the elevated plus maze test (EPM) revealed a reduction in anxiety-like behaviors (by an increased number of entries into the open arm, percentage of time spent in the open arm, and rearing and freezing) among stressed animals upon receiving injections of phentolamine into the BLA. The open-field test results (increased rearing, grooming, and freezing behaviors) were consistent with the EPM test results. Phentolamine infusion into the BLA enhanced spatial memory, reducing errors in finding the target hole and decreasing latency time in the Barnes maze test for stress and nonstress conditions. Injecting phentolamine into the BLA on both sides effectively prevented LTP impairment in hippocampal CA1 neurons after being subjected to foot-shock stress. It has been suggested that phentolamine in the BLA can effectively improve anxiety-like behaviors and memory deficits induced by foot-shock stress.

Neuroprotective Effect of Ixeris dentata Extract on Trimethyltin-Induced Memory Impairment in Rats

Alzheimer’s disease (AD) is a representative neurodegenerative disease characterized by the structural and functional degeneration of neurons. The present study investigated the neuroprotective effect of Ixeris dentata (ID) extract on trimethyltin (TMT)-induced memory deficit in the rat. Cognitive improving effect and neuronal activity of ID were assessed by using Morris water maze (MWM) test and choline acetyltransferase (ChAT), cAMP-response element-binding protein (CREB) immunohistochemistry. Seven days after TMT injection (8.0 mg/kg, i.p.), each group of rats was administered saline, water extract of ID (WID, 400 or 800 mg/kg, p.o.), ethanol extract of ID (EID, 400 or 800 mg/kg, p.o.), or caffeic acid (CAF, 30 mg/kg, i.p.) daily for fourteen days. Results: Treatment with EID and CAF produced a significant improvement in escape latency time of the acquisition, and retention time in the target area of the MWM task. Additionally, administration of EID or CAF markedly alleviated TMT-induced loss of ChAT- and CREB-immunoreactive cells in the hippocampus. The results demonstrated that EID has a protective effect against TMT-induced memory deficit, partly through increasing the CREB and cholinergic signaling pathway in the hippocampus. These results suggest that ethanol extracts of ID might be useful for improving cognitive functions in neurodegenerative diseases such as Alzheimer’s disease.

Licochalcone A Ameliorates Cognitive Dysfunction in an Alzheimer's Disease Model by Inhibiting Endoplasmic Reticulum Stress-Mediated Apoptosis.

Endoplasmic reticulum (ER) stress-induced neurodegeneration has been considered an underlying cause of Alzheimer disease (AD). Here, we investigated the beneficial effects of licochalcone A (Lico A), a valuable flavonoid of the root of the Glycyrrhiza species, against cognitive impairment in AD by regulating ER stress. The triple transgenic mouse AD models were used and were administrated 5 or 15mg/kg Lico A. Cognitive deficits, Aβ deposition, ER stress, and neuronal apoptosis were determined using Morris Water Maze test, probe trial, immunofluorescence staining, western blotting, and TUNEL staining. To investigate the mechanisms of how Lico A exerts anti-AD effects, primary hippocampal neurons were isolated from the AD model mice and treated with Lico A, salubrinal, an eIF2α phosphatase inhibitor, ML385, a Nrf2 inhibitor, or LY294002, an inhibitor of PI3K. Pharmacokinetics and toxicity of Lico A (15mg/kg) in AD mice were evaluated. We found that Lico A improved cognitive impairment, decreased Aβ plaques, inhibited ER stress, and reduced neuronal apoptosis in the hippocampus and cortex of AD mice. Treatment with Lico A in primary hippocampal neurons exerted the same effects as it did in vivo. Additionally, cotreatment with ML385 or LY294002 significantly impeded the effects of Lico A against ER stress. Moreover, 15mg/kg Lico A had a good bioavailability and low toxicity in AD mice. Our results demonstrated that Lico A ameliorates ER stress-induced neuronal apoptosis by inhibiting PERK/eIF2α/ATF4/CHOP signaling, suggesting the therapeutic potential of Lico A in AD treatment.

Dexmedetomidine alleviates the long-term neurodevelopmental toxicity induced by sevoflurane in the developing brain.

Sevoflurane is an extensively used anesthetic for pediatric patients, however, numerous studies showed that sevoflurane (SEVO) may cause long-term neurodevelopmental toxicity. Dexmedetomidine (DEX) has been shown to be protective against SEVO-induced neurotoxicity, but the mechanism remains unclear. The effects and mechanisms of different DEX administration routes on SEVO-induced neurotoxicity and long-term cognitive defects were determined and further investigated the role of sex in these processes. Male and female Sprague Dawley (SD) rats at postnatal day 7 (PND7) received an intraperitoneal injection of DEX (10 μg/kg) before or after exposure to 2.5% SEVO for 6 hours, or before and after SEVO exposure. The respiratory and mortality rates of the pups were recorded during anesthesia. Neuroapoptosis was evaluated by TdT-mediated dUTP Nick-End labeling (TUNEL) staining. Immunohistochemistry and immunofluorescence were employed to detect the expression of caspase-3 in neuronal cells and neurons. The expression of GSK-3β and DISC1 were determined by Western blotting or RT-qPCR. Morris Water Maze (MWM) test was used to evaluate the learning and memory ability of rats until they were 3 weeks and 5 weeks old. Compared with the control group, exposure to 2.5% SEVO resulted in increased neuroapoptosis, and decreased the expression of DISC1 at levels of mRNA and protein and phosphorylated GSK-3β in the developing brain. SEVO exposure during critical neurodevelopmental periods could cause persistent cognitive defects in adolescent male and female rats, and inhibited DISC1 and phosphorylated GSK-3β protein expression. The neurotoxic impacts of SEVO were lessened by the administration of DEX (10 μg/kg) before or after exposure. Our findings suggest that DEX (10 μg/kg) mitigates the neurotoxic effects of SEVO on the developing rat brain as well as postnatal cognitive defects by regulating the DISC1/GSK-3β signaling.

Intervention effects of Naoxintong capsules on psychological and cardiac status in depressed rats after heart failure

Abstract Background Depression is a common clinical phenomenon in the patients with heart failure (HF). In traditional Chinese medicine (TCM), diseases in the brain and heart are thought to be correlated and interact. Naoxintong capsules (NXT) has been used for treating cardio-cerebrovascular diseases, while its therapeutic effect on depression after HF remains unclear. Objective The aim of the study is to evaluate the intervention effect of NXT on depression after HF. Methods Sprague-Dawley rats were assigned into the following 5 groups: sham, model, NXT (250, 1000 mg/kg), and valsartan (8 mg/kg). Coronary artery occlusion was performed to induce HF and subsequent depression in rats. The cardiac function was evaluated by echocardiography, hematoxylin-eosin staining, and Masson trichrome staining. The sucrose preference test and Morris water maze test were carried out to assess the depressive behaviors in rats. The ultrastructure of hippocampal CA1 neurons was observed and the levels of corticotropin-releasing hormone in the hypothalamus, brain-derived neurotrophic factor in the cortex, and adrenocorticotropic hormone (ACTH) in the plasma were determined by enzyme-linked immunosorbent assay. The levels of dopamine, 5-hydroxytryptamine, norepinephrine, and γ-aminobutyric acid in the hippocampus were measured by UPLC-QQQ-MS. Results NXT reduced myocardial injury and pathological changes in the cardiac tissue and increased the left ventricular ejection fraction, left ventricular fractional shortening, and cardiac output. NXT increased the sugar preference rate and number of crossings and shortened the escape latency. Furthermore, the NXT treatment restored the levels of corticotropin-releasing hormone, adrenocorticotropic hormone, brain-derived neurotrophic factor, dopamine, and γ-aminobutyric acid to the baseline values. Conclusions NXT not only demonstrates cardioprotective effect but also attenuates depression in the rats after HF. It may exert the antidepressant effect by inhibiting the hyperactivity of the hypothalamic-pituitary-adrenal axis and recovering the levels of neurotrophic factors and neurotransmitters.

Ouabain Ameliorates Alzheimer’s Disease-Associated Neuropathology and Cognitive Impairment in FAD4T Mice

Background: Alzheimer’s disease (AD) is a common clinical neurodegenerative disorder, primarily characterized by progressive cognitive decline and behavioral abnormalities. The hallmark pathological changes of AD include widespread neuronal degeneration, plaques formed by the deposition of amyloid β-protein (Aβ), and neurofibrillary tangles (NFTs). With the acceleration of global aging, the incidence of AD is rising year by year, making it a major global public health concern. Due to the complex pathology of AD, finding effective interventions has become a key focus of research. Ouabain (OUA), a cardiac glycoside, is well-known for its efficacy in treating heart disease. Recent studies have also indicated its potential in AD therapy, although its exact mechanism of action remains unclear. Methods: This study integrates bioinformatics, multi-omics technologies, and in vivo and in vitro experiments to investigate the effects of OUA on the pathophysiological changes of AD and its underlying molecular mechanisms. Results: This study analyzed the expression of the triggering receptor expressed on myeloid cells 2 (TREM2) across different stages of AD using bioinformatics. Serum samples from patients were used to validate soluble TREM2 (sTREM2) levels. Using an Aβ1-42-induced microglial cell model, we confirmed that OUA enhances the PI3K/AKT signaling pathway activation by upregulating TREM2, which reduces neuroinflammation and promotes the transition of microglia from an M1 proinflammatory state to an M2 anti-inflammatory state. To evaluate the in vivo effects of OUA, we assessed the learning and memory capacity of FAD4T transgenic mice using the Morris water maze and contextual fear conditioning tests. We used real-time quantitative PCR, immunohistochemistry, and Western blotting to measure the expression of inflammation-associated cytokines and to assess microglia polarization. OUA enhances cognitive function in FAD4T mice and has been confirmed to modulate microglial M1/M2 phenotypes both in vitro and in vivo. Furthermore, through bioinformatics analysis, molecular docking, and experimental validation, TREM2 was identified as a potential target for OUA. It regulates PI3K/Akt signaling pathway activation, playing a crucial role in OUA-mediated M2 microglial polarization and its anti-inflammatory effects in models involving Aβ1-42-stimulated BV-2 cells and FAD4T mice. Conclusions: These findings indicate that OUA exerts anti-neuroinflammatory effects by regulating microglial polarization, reducing the production of inflammatory mediators, and activating the PI3K/Akt signaling pathway. Given its natural origin and dual effects on microglial polarization and neuroinflammation, OUA emerges as a promising therapeutic candidate for neuroinflammatory diseases such as AD.

Yigong San improves learning and memory functions of APP/PS1 transgenic mice by regulating brain fluid metabolism

To explore the mechanism by which Yigong San (YGS) improves learning and memory abilities of APP/PS1 transgenic mice in light of cerebral fluid metabolism regulation. Three-month-old male APP/PS1 transgenic mice and wild-type C57BL/6 mice were both randomized into control group, model group, donepezil (1.67 mg/kg) group, and YGS (7.5 g/kg) group and received the corresponding treatments via gavage once daily for one month. After the treatments, the mice were assessed for learning and memory functions using Morris water maze test and examined for hippocampal and cortical pathologies and amyloid plaques using HE, immunohistochemical and thioflavin S staining; ELISA and Evans blue method were used for detecting Aβ1-40 and Aβ1-42 levels in the brain tissue and serum and assessing blood-brain barrier (BBB) integrity. Immunofluorescence colocalization was used to investigate AQP4 polarization on astrocytes. Western blotting was performed to detect the expressions of VE-cadherin, ZO-1, occludin, β-amyloid precursor protein (APP), BACE1, insulin-degrading enzyme (IDE), LRP1, RAGE, and AQP4 proteins. Compared with the control mice, APP/PS1 mice showed significant impairment of learning and memory abilities, increased degeneration or necrosis of hippocampal and cortical neurons, pathological scores, Aβ-positive plaques, elevated Aβ1-40 and Aβ1-42 levels in the brain tissue and serum, increased BBB permeability, upregulated RAGE expression, lowered expressions of VE-cadherin, LRP1, ZO-1, occludin, and AQP4 proteins, and reduced AQP4- expressing GFAP-positive cells. YGS treatment significantly improved the performance of the transgenic mice in Morris water maze test, reduced hippocampal and cortical pathologies and Aβ-positive plaques, and ameliorated the abnormal changes in Aβ1-40 and Aβ1-42 levels, BBB permeability, protein expressions of RAGE, VE-cadherin, LRP1, ZO-1, occludin and AQP4, and the number of AQP4-expressing GFAP-positive cells. YGS improves learning and memory changes in APP/PS1 mice by ameliorating neuronal damage and Aβ pathology in the brain and regulating brain fluid metabolism.

Tinnitus Generation and Behavioral Changes Caused by Chronic Stress: A Behavioral and Brain Study in a Rat Model.

This study explores the connection between chronic stress and tinnitus, a phantom auditory perception, using an animal model. Rats were subjected to 2 h of daily restraint stress for 10 days. Tinnitus was assessed on the last day of stress exposure using the gap response of pre-pulse inhibition acoustic reflex, measured at 60 dB background sound level at 8, 16, and 20 kHz. Chronic stress-exposed rats were categorized into two groups: tinnitus (RTG) and non-tinnitus (RNTG). Various tests, including hearing assessments (distortion product otoacoustic emissions and auditory brainstem response), behavioral evaluations (elevated plus maze test and forced swimming test), and immunohistochemical studies in the auditory and limbic brain regions, were conducted to understand the relationship between chronic stress, tinnitus, and behavioral changes. Following chronic restraint stress, 64.3% of the rats exhibited tinnitus with no audiometric changes. EPM and FST indicated an increase of anxiety- and depression-related behavior in RTG. Immunohistochemical analyses identified specific alterations in the expression of neurotransmitter receptors within brain regions implicated in tinnitus. Specifically, we observed a decrease in γ-aminobutyric acid A receptor α1 expression and an increase in glutamate receptor (N-methyl-D-aspartate receptor subunit 1 and receptor subunit 2B) expression in specific brain region. These changes suggest a reorganization of neural circuits associated with the tinnitus generation and behavioral changes of the rats after chronic stress exposure. Chronic stress alone can be a causal factor for the generation of tinnitus and behavioral changes through altered neural activities in tinnitus-related brain networks. NA Laryngoscope, 2024.

Regulating the NMDA/NR2B signaling pathway mediates anticonvulsant, antineuroinflammation, and anti-oxidative stress effects of 1,3,benzothiazole derivative 1M in pentylenetetrazole-induced kindling in mice.

Periodic epileptic episodes are the hallmark of epilepsy, a prevalent neurological disorder. Research suggests a significant correlation between neuroinflammation and oxidative stress in a variety of neurological diseases, such as epilepsy. A substantial amount of evidence supports the role of N-methyl-D-aspartate receptors (NMDARs) in the progression of epilepsy. Although several lines of research have disclosed numerous biochemical effects of early seizures, its connection with disturbed NMDAR/NR2B subunit expression remains unclear. 2-Mercaptobenzothiazole (MBT) is a vital scaffold with several biological activities, and its various substitutes show promising anti-inflammatory potential. The current study aimed to investigate the newly synthesized 1,3-(benzothiazole-2-sulfanyl)-1-(morpholine-4-yl)ethan-1-one (1M), a substituted MBT, for its neuroprotective potential in a mice model of pentylenetetrazole-induced epilepsy (PTZ), by modulating NMDA/NR2B pathway. The compound was tested for docking and simulation analysis, demonstrating a solid and stable bond with the NR2B subunit of NMDA. To ascertain the effects of 1M, as well as to further illustrate its mechanism of neuroprotection via NMDA/NR2B in PTZ-induced kindling model, mice of either sex were given two doses of test compound, 1M (10mg/kg and 20mg/kg). The behavioral assessments were evaluated using open-field, Y-maze, and elevated-plus maze tests, which indicated improved behavioral alterations caused by PTZ after 1M treatment. The antioxidant profiling was done by estimating glutathione-S-transferase (GST), catalase (CAT), reduced glutathione (GSH), and LPO (lipid peroxidation) in hippocampal tissues, where the test compound 1M significantly restored the depleted antioxidants, showcasing its antioxidant potential. Moreover, the cellular morphological damages induced by PTZ were detected by H&E staining, which was rescued after 1M administration. Furthermore, the activation of the inflammatory pathway was confirmed by quantitative analysis of inflammatory mediators tumor necrotic factor (TNF-α), nuclear factor kappa B (NF-κB), and cylooxegenase2 (COX-2) by enzyme-linked immunosorbent assay (ELISA), where 1M administration significantly ameliorated their expression. Furthermore, to demonstrate the involvement of the NR2B pathway, NR2B-antagonist ifenprodil was employed, and results were further confirmed through RT-PCR analysis. Our results, when considered collectively, indicate that 1M may act by inhibiting the NR2B subunit of the NMDA receptor, subsequently mitigating downstream oxidative stress and inflammatory mediators through various pathways.

Discovery of novel substituted (Z)-N′-hydroxy-3-(3-phenylureido)benzimidamide derivatives as multifunctional molecules targeting pathological hallmarks of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder marked by significant loss of central cholinergic neurons. This progressive deterioration leads to cognitive dysfunction and impaired motor activity, culminating in the brain cell's death at the later stages of the disease. The approved drugs for AD are limited to providing symptomatic relief for an initial period due to the multifaceted etiology of the disease. Several studies have demonstrated that rivastigmine (RIV) is a selectively potent inhibitor of butyrylcholinesterase and devoid of antioxidant, Aβ, and tau protein aggregation inhibition and anti-inflammatory properties. Therefore, to address these issues associated with RIV, novel rivastigmine-based molecules were rationally designed, synthesized, and evaluated in various in-vitro and in-vivo AD models. In in-vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition studies revealed that 3q &6e as promising leads (AChE, IC50 1.72 ± 0.15, 0.91 ± 0.016 μM, BChE, IC50 6.69 ± 0.28 μM, 1.19 ± 0.026 μM, for 3q &6e, respectively). The computational studies (molecular docking and dynamics) further corroborated the in-vitro studies. Further, 3q and 6e were found to be potent antioxidants in the DPPH assay (IC50 16.15 ± 1.05 & 15.17 ± 0.07 μM, for 3q &6e, respectively). Interestingly, 3q, and 6e could effectively inhibit self-induced full-length tau and Aβ1-42 aggregation. Treatment with 3q &6e inhibited microglial activation by attenuating ROS release and mitochondrial damage. Further, 3q &6e also suppressed NLRP3 inflammasome and NF-κB expression levels in microglial cells and halted the release of pro-inflammatory cytokines in human microglial cells. Finally, 3q &6e were found to be efficacious in reversing the scopolamine-induced memory impairment in the Morris water maze test. The expression of various neuroprotection markers, such as BDNF and TRKB, was significantly overexpressed compared to the disease control group.

WuYou decoction effectively reduces neuronal damage, synaptic dysfunction, and Aβ production in rats exposed to chronic sleep deprivation by modulating the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway

Ethnopharmacological relevanceChronic sleep deprivation (CSD) can result in neuronal damage, synaptic dysfunction, Aβ production, neuroinflammation, and ultimately cognitive deterioration. WuYou Decoction (WYD), a contemporary prescription, has shown promise in enhancing sleep quality and cognitive performance in individuals with insomnia. However, the specific molecular mechanisms responsible for the neuroprotective effects of WYD on CSD remain incompletely understood. Aim of the studyThis study aimed to investigate the neuroprotective effects of WYD on the CSD model and its molecular mechanism. Materials and methodsUHPLC-MS/MS analysis was utilized to analyze the active ingredients of WYD extract. The study employed the multi-platform water environment method to establish the CSD model in rats. Subsequent to treatment with varying doses of WYD in CSD rats, cognitive function and pathological alterations in hippocampus and cortex, including neuronal damage, synaptic dysfunction, Aβ production, and neuroinflammation, were evaluated through a combination of Morris Water Maze test, HE staining, Nissl staining, Golgi-Cox staining, Transmission electron microscope, ELISA, Immunohistochemistry staining, Immunofluorescence staining and Western blot. ResultsUHPLC-MS/MS analysis revealed a total of 99 active ingredients were identified from the WYD extract. The administration of WYD exhibited a mitigation of cognitive decline in the model of CSD, as evidenced by increased neuron count in the hippocampus and cortex, and improved density and length of dendritic spines in these brain regions. Furthermore, WYD was found to suppress the Aβ production, and inhibit the expression of BACE1, PS1, GFAP, IBA1, IL-1β, IL-6, TNF-α, phosphorylated IκBα (Ser32) and phosphorylated NF-κB p65 (Ser536) in the hippocampus and cortex, while also increasing the levels of PSD95, SYN1, ADAM10, IDE, SIRT1 and Nrf2. ConclusionsWYD exhibits neuroprotective properties in CSD, potentially through modulation of the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway.

Agmatine Improves Oxidative Stress Profiles in Rat Brain Tissues Induced by Sodium Azide

Introduction: The brain is highly susceptible to oxidative damage due to excessive oxygen tension, a high concentration of oxidizable substrates, and low antioxidant capacity. Consequently, oxidative stress is linked to several brain disorders and neurodegeneration. Sodium azide is a cytochrome oxidase inhibitor that promotes neurodegeneration by enhancing the release of excitotoxins and inducing oxidative stress through the peroxidation of membrane lipids. This process results in the release of intra-mitochondrial Ca+2 and H2O2 (ROS Dependent-Ca+2 release). Agmatine, a biogenic amine, is also referred to as a free radical scavenger, protecting the brain from membrane collapse, apoptosis, and mitochondrial swelling. Objective: This study was designed to identify the antioxidative effects of agmatine on sodium azide- induced oxidative stress in brain tissues. Methodology: Twenty-four male albino Wistar rats were allocated into two groups: a control group receiving water and a test group administered sodium azide (5 mg/kg, intraperitoneally) for a duration of 14 days. Subsequently, the animals were further subdivided and treated for an additional two weeks with either water or agmatine (100 mg/kg). Behavioral assessments were performed onehour post-agmatine administration, and brain homogenates were prepared for biochemical analyses. Results: The agmatine-treated group exhibited a significant increase (P&lt;0.01) in both the number of entries and the time spent in the light box and the open arms of the light/dark transition box and elevated plus maze tests, respectively. Additionally, agmatine administration significantly enhanced (P&lt;0.01) the total number of squares crossed in the open field test. Biochemical assessments revealed that agmatine treatment significantly reduced (P&lt;0.01) the levels of reactive oxygen species and malondialdehyde. Moreover, it significantly increased (P&lt;0.01) the levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and glutathione compared to the control group. Conclusion: The present study revealed that agmatine has substantial effects on oxidative and antioxidant enzyme levels in sodium azide-induced oxidative stress. Agmatine-treated rats exhibited decreased reactive oxygen species levels and improvements in behavioral impairments resulting from sodium azide administration.

Plasma neurofilament heavy chain is a prognostic biomarker for the development of severe epilepsy after experimental traumatic brain injury.

This study was undertaken to test whether the postinjury plasma concentration of phosphorylated neurofilament heavy chain (pNF-H), a marker of axonal injury, is a prognostic biomarker for the development of posttraumatic epilepsy. Tail vein plasma was sampled 48 h after traumatic brain injury (TBI) from 143 rats (10 naïve, 21 controls, 112 with lateral fluid percussion injury) to quantify pNF-H by enzyme-linked immunosorbent assay. During the 6th postinjury month, rats underwent 30 days of continuous video-electroencephalographic monitoring to detect unprovoked seizures and evaluate epilepsy severity. Somatomotor (composite neuroscore) and spatial memory (Morris water maze) testing and quantitative T2 magnetic resonance imaging were performed to assess comorbidities and lesion severity. Of the 112 TBI rats, 25% (28/112) developed epilepsy (TBI+) and 75% (84/112) did not (TBI-). Plasma pNF-H concentrations were higher in TBI+ rats than in TBI- rats (p < .05). Receiver operating characteristic curve analysis indicated that plasma pNF-H concentration distinguished TBI+ rats from TBI- rats (area under the curve [AUC] = .647, p < .05). Differentiation was stronger when comparing TBI+ rats exhibiting severe epilepsy (≥3 seizures/month) with all other TBI rats (AUC = .732, p < .01). Plasma pNF-H concentration on day 2 (D2) distinguished TBI+ rats with seizure clusters from other TBI rats (AUC = .732, p < .05). Higher plasma pNF-H concentration on D2 after TBI correlated with lower neuroscores on D2 (p < .001), D6 (p < .001), and D14 (p < .01). Higher pNF-H concentration on D2 correlated with greater T2 signal abnormality volume on D2 (p < .001) and D7 (p < .01) and larger cortical lesion area on D182 (p < .01). Plasma pNF-H concentration on D2 did not correlate with Morris water maze performance on D37-D39. Plasma pNF-H is a promising clinically translatable prognostic biomarker for the development of posttraumatic epilepsy with frequent seizures or seizure clusters.