Hippocampal Tissue Research Articles

Lindera aggregata improves intestinal function and alleviates depressive behaviors through the BDNF/TrkB/CREB signaling pathway induced by CUMS in mice

Depression is a common mental illness, which is highly related to intestinal motor dysfunction and causes a global burden of disease. Lindera aggregata (LA), a traditional medicinal herb, has been used to treat gastrointestinal disorders; however, the effect of LA on depression remains unclear. Here, we assessed the impact of LA on chronic unpredictable mild stress (CUMS)-induced depression in mice and explored the related mechanisms. The results showed that LA ameliorated depressive behaviors in mice exposed to CUMS, as evidenced by improved performance in the sucrose preference test, force swimming test, and open field test, as well as increased serum levels of adrenocorticotropic hormone and 5-hydroxytryptamine. In addition, LA increased the serum levels of D-xylose and ghrelin, indicating that LA can promote gastrointestinal motility. Additional studies revealed that LA relieved CUMS-induced hippocampal tissue damage, as shown by hematoxylin and eosin and Nissl staining. LA increased the expression levels of brain-derived neurotrophic factor (BDNF) and promoted the activation of tropomyosin receptor kinase B (TrkB) and cAMP response element-binding (CREB) in the hippocampus of CUMS-exposed mice or in corticosterone-injured HT22 cells. In conclusion, LA can improve CUMS-induced depressive behavior in mice, potentially through hippocampal neuroprotection mediated by the BDNF/TrkB/CREB signaling pathway, which also contributes to improved intestinal function.

Kaixinsan regulates neuronal mitochondrial homeostasis to improve the cognitive function of Alzheimer's disease by activating CaMKKβ-AMPK-PGC-1α signaling axis

BackgroundAlzheimer's disease (AD) is a neurodegenerative disease primarily characterized by cognitive impairments. With the intensification of population aging, AD has become a major health issue faced by the elderly. Kaixinsan, a classical traditional Chinese prescription consists of Panax ginseng C. A. Mey., Polygala tenuifolia Willd., Poria cocos (Schw.) Wolf and Acori Tatarinowii rhizoma, is commonly used in clinical for treating memory decline. However, its mechanism remains unclear, which hinders its popularization and application. MethodMorris water maze (MWM) was performed to evaluate the effect of Kaixinsan on improving learning and memory ability in SAMP8 (senescence-accelerated mouse prone 8, an AD model mice) mice. Nissl staining, TdT-mediated dUTP Nick End Labeling (TUNEL) and western blotting (Bax and Bcl-2) were used to confirm the effect of Kaixinsan on the neuronal structure and apoptosis of SAMP8 mice. ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was performed to identify the distribution components of the brain tissue after receiving Kaixinsan extraction. Based on the identified brain distribution components, the mechanism of Kaixinsan improving the cognitive function was predicted by network pharmacology. Then, using HSP60 as mitochondrial marker and RBFOX3 as neuron marker, immunofluorescence co-localization was used to confirm the effect of Kaixinsan on neuronal mitochondria quantity in SAMP8 mice. Using western blotting to detect the expression of predicted proteins (AMPK, CaMKKβ, PGC-1α and HSP90) affecting mitochondrial homeostasis. To further confirm the mechanism of Kaixinsa. The authors replicated SH-SY5Y cell injury model induced by Amyloid β - protein fragment 25-35 (Aβ25-35) and compared the effects of serum containing Kaixinsan on apoptosis of injured SH-SY5Y cells (detected by flow cytometer) and the expression level of apoptosis-associated protein (Bax and Bcl-2) and mitochondrial homeostasis related proteins (AMPK, CaMKKβ, PGC-1α and HSP90), with or without the addition of CaMKKβ inhibitor (STO-609). ResultsThe results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice, alleviate the hippocampal tissue lesions and inhibit neuron apoptosis. Seventeen brain distribution components of Kaixinsan were identified. Based on the brain distribution components of Kaixinsan, the results of network pharmacology suggest that Kaixinsan may regulate mitochondrial homeostasis through the CaMKKβ-AMPK-PGC-1α signaling axis. In vivo experiments, The authors observed that Kaixinsan could reverse neuronal mitochondrial loss in SAMP8 mice by upregulating CaMKKβ, AMPK, HSP90 and PGC-1α to promote mitochondrial biogenesis and increase the number of neuronal mitochondria. Additionally, the in vitro experiments demonstrated that Kaixinsan can inhibit apoptosis of Aβ25-35 injured SH-SY5Y cells and upregulate mitochondrial homeostasis-related proteins CaMKKβ, AMPK and PGC-1α. However, in addition to CaMKKβ inhibitors, the neuroprotective effect disappeared. ConclusionThe results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice by regulating CaMKKβ-AMPK-PGC-1α signaling axis to maintain mitochondrial homeostasis and inhibit neuronal apoptosis.

Paternal preconception donepezil exposure enhances learning in offspring

BackgroundRecent research has indicated that parental use of central nervous system-targeting medications during periconceptional periods may affect offspring across various developmental and behavioral domains. The present study sought to investigate the potential influence of paternal use of donepezil, a specific reversible central acetylcholinesterase inhibitor that activates the cholinergic system to promote cognition, on offspring.ResultsIn this study, male rats were bred after 21 days of oral donepezil administration at a dose of 4 mg/kg to generate F1 offspring. Both male and female F₁ offspring displayed enhanced performance in learning and short-term memory tests, including novel object recognition, Y maze, and operant learning. Transcriptomic analysis revealed notable alterations in genes associated with the extracellular matrix in the hippocampal tissue of the F1 generation. Integration with genes related to intelligence identified potential core genes that may be involved in the observed behavioral enhancements.ConclusionsThese findings indicate that prolonged paternal exposure to donepezil may enhance the learning and memory abilities of offspring, possibly by targeting nonneural, extracellular regions. Further research is required to fully elucidate any potential transgenerational effects.

Exploring Liraglutide in Lithium-Pilocarpine-Induced Temporal Lobe Epilepsy Model in Rats: Impact on Inflammation, Mitochondrial Function, and Behavior.

Background/Objectives: Glucagon-like peptide-1 receptor agonists such as liraglutide are known for their neuroprotective effects in neurodegenerative disorders, but their role in temporal lobe epilepsy (TLE) remains unclear. We aimed to investigate the effects of liraglutide on several biological processes, including inflammation, antioxidant defense mechanisms, mitochondrial dynamics, and function, as well as cognitive and behavioral changes in the TLE model. Methods: Low-dose, repeated intraperitoneal injections of lithium chloride-pilocarpine hydrochloride were used to induce status epilepticus (SE) in order to develop TLE in rats. Fifty-six male Sprague Dawley rats were subjected and allocated to the groups. The effects of liraglutide on inflammatory markers (NLRP3, Caspase-1, and IL-1β), antioxidant pathways (Nrf-2 and p-Nrf-2), and mitochondrial dynamics proteins (Pink1, Mfn2, and Drp1) were evaluated in hippocampal tissues via a Western blot. Mitochondrial function in peripheral blood mononuclear cells (PBMCs) was examined using flow cytometry. Cognitive-behavioral outcomes were assessed using the open-field, elevated plus maze, and Morris water maze tests. Results: Our results showed that liraglutide modulates NLRP3-mediated inflammation, reduces oxidative stress, and triggers antioxidative pathways through Nrf2 in SE-induced rats. Moreover, liraglutide treatment restored Pink1, Mfn2, and Drp1 levels in SE-induced rats. Liraglutide treatment also altered the mitochondrial function of PBMCs in both healthy and epileptic rats. This suggests that treatment can modulate mitochondrial dynamics and functions in the brain and periphery. Furthermore, in the behavioral aspect, liraglutide reversed the movement-enhancing effect of epilepsy. Conclusions: This research underscores the potential of GLP-1RAs as a possibly promising therapeutic strategy for TLE.

Obtaining a Single-Cell Suspension from Mouse Hippocampal Tissue

Obtaining a Single-Cell Suspension from Mouse Hippocampal Tissue

Obtaining a Single-Cell Suspension from Mouse Hippocampal Tissue

Obtaining a Single-Cell Suspension from Mouse Hippocampal Tissue

Investigating the modulatory effects of lactoferrin on depressed rats through 16S rDNA gene sequencing and LC-MS metabolomics analysis.

Lactoferrin is a natural multifunctional glycoprotein with potential antidepressant-like effects. However, the mechanism of its antidepressant effect has not been explored from the perspective of gut flora metabolism. Therefore, we employed both 16S rDNA gene sequencing and LC-MS metabolomics analysis to investigate the regulatory effects and mechanisms of lactoferrin in a rat model of depression. After one week of acclimatization, twenty-four 7-week-old male Sprague-Dawley rats were randomly and equally assigned into three groups: the control group, the model group, and the lactoferrin intervention group. The control group rats were housed under standard conditions, while the rats in the model and lactoferrin intervention groups were individually housed and exposed to chronic unpredictable mild stress for 44days simultaneously. The lactoferrin intervention group was provided with water containing 2% lactoferrin (2g/100ml). Behavioural tests were conducted at week 7. Upon completion of the behavioral tests, the rats were anesthetized with isoflurane, humanely euthanized using a rat guillotine, and tissue samples were collected for further experiments. The results indicated that lactoferrin intervention led to an increase in sucrose solution consumption, horizontal movement distance, number of cross platforms, and residence time in the target quadrant. Additionally, it resulted in an increase in jejunal tight junction protein ZO-1 expression and a suppression of serum expression of inflammatory factors, Lipopolysaccharide and Diamine oxidase. In summary, lactoferrin can regulate the metabolic disorder of intestinal flora, reduce intestinal permeability, and further regulate the metabolic balance of hippocampal tissues through the microbiota-gut-brain axis. This process ultimately alleviates the depression-like behavior in rats.

Enhancement of cognitive function in mice with Alzheimer's disease through hyperbaric oxygen-induced activation of cellular autophagy.

In this study, we examined the effectiveness of hyperbaric oxygen (HBO) therapy in ameliorating cognitive deficits in mice with Alzheimer's disease (AD), while also assessing its impact on the autophagic pathway within the context of AD. 20 double-transgenic mice expressing the amyloid precursor protein and presenilin 1 (APP/PS1) were purposefully selected and randomly assigned to groups A and B. Concurrently, 20 C57BL/6 mice were chosen and randomly categorized into groups C and D, each consisting of 10 mice. Mice in groups B and D received HBO treatment. The Morris water maze assay was used to assess changes in mouse behavior. Immunohistochemistry techniques were used to quantify the expression levels of amyloid-beta 42 (Aβ42) and microtubule-associated protein 1A/1B-light chain 3 (LC3) in hippocampal tissues, while western blot analysis was used to investigate the levels of LC3-II, p62, phosphoinositide 3-kinase (PI3K), and mammalian target of rapamycin (mTOR) proteins within hippocampal tissues. Mice allocated to group B exhibited reduced escape latency and prolonged dwell time in the target quadrant compared to other groups. Histological examination revealed conspicuous plaque-like deposits of Aβ42 in the hippocampal tissues of mice in groups A and B. Group B displayed diminished Aβ42-positive reactants and augmented microtubule-associated protein 1A/1B-LC3-positive reactants compared to group A. LC3-positive reactants were also detected in the hippocampal tissues of mice in groups C and D, surpassing the levels observed in groups A and B. Furthermore, group B demonstrated significantly lower expression of mTOR protein and markedly higher expression of LC3-II protein in mouse hippocampal tissues when compared to group A (P < 0.05). Conversely, there were no significant disparities noted in PI3K and p62 protein expression between groups B and A. Notably, no discernible discrepancies were observed in the expression levels of mTOR, PI3K, LC3-II, and p62 proteins between groups C and D within mouse hippocampal tissues. HBO treatment demonstrates efficacy in enhancing cognitive function in mice with AD and holds promise as a potential therapeutic intervention for AD by facilitating the activation of the mTOR pathway-mediated autophagy.

Novel insights into sevoflurane-induced developmental neurotoxicity mechanisms.

Aim: This study explores Sevoflurane (Sevo)-induced neurotoxicity mechanisms in neonates through transcriptome sequencing and models.Methods: Seven-day-old mice were exposed to 3% Sevo, and hippocampal tissue was collected for analysis of differentially expressed lncRNAs and mRNAs compared with normal mice. MiR-152-3p was selected, and the interaction between H19, USP30, and miR-152-3p was explored in BV2 microglial cells and mouse hippocampal neurons.Results: Sevo disrupts mitochondrial autophagy via USP30 upregulation, exacerbating neurotoxicity and activating NLRP1 inflammasome-mediated inflammation.Conclusion: Sevo neurotoxicity is mediated through the H19/miR-152-3p/USP30 axis, implicating microglial regulation of neuronal pyroptosis.

Remimazolam attenuates lipopolysaccharide-induced neuroinflammation and cognitive dysfunction

ObjectiveRemimazolam, a novel benzodiazepine, is widely used as an anesthetic in endoscopic procedures; however, its effects on cognitive function remain unclear, limiting its broader application in general anaesthesia. Neuroinflammation is a well-established key factor in the etiology and progression of cognitive dysfunction, including conditions such as Alzheimer's disease, Parkinson's disease, postoperative delirium, and postoperative cognitive dysfunction. Preclinical studies have demonstrated that remimazolam exerts anti-inflammatory and neuroprotective effects, and clinical reports indicate a reduced incidence of postoperative delirium in patients treated with remimazolam. Nevertheless, whether remimazolam improves cognitive function through its anti-inflammatory properties remains uncertain. This study aimed to investigate the neuroprotective effects of remimazolam and its underlying mechanism in a lipopolysaccharide (LPS)-induced model of neuroinflammation, neuronal injury, and cognitive dysfunction MethodsC57BL/6 J male mice were administered LPS intraperitoneally to establish a model of neuroinflammation-induced cognitive impairment. A subset of mice received remimazolam via intraperitoneal injection 30 minutes prior to LPS administration. Cognitive performance was evaluated using behavioural tests, including the Morris Water Maze (MWM), Novel Object Recognition (NOR) test, and Open Field Test (OFT). Hippocampal tissues were analyzed by haematoxylin-eosin (HE) staining to assess structural changes. Inflammatory markers, including Interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, were quantified using enzyme-linked immunosorbent assay (ELISA) and real-time quantitative PCR. Immunofluorescence was used to detect translocator protein (TSPO) and markers of microglia activation (IBA-1, CD16/32, and CD206). Results(1) Remimazolam reversed LPS-induced cognitive deficits, as evidenced by shorter spatial exploration latency and increased platform crossings in the MWM, and an elevated recognition index in the NOR test. (2) Remimazolam improved hippocampal morphology, reducing LPS-induced neuronal damage. (3) Remimazolam significantly decreased levels of hippocampal inflammatory cytokines, inhibited microglial activation, promoted M2-type microglia polarization, and increased TSPO expression. ConclusionRemimazolam demonstrated neuroprotective and anti-neuroinflammatory effects in a mouse model of LPS-induced cognitive impairment. These effects are likely mediated through the regulation of TSPO, which inhibits microglial activation and promotes the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype.

Study on the interventional effects of Chlamydomonas reinhardtii peptides on chronic unpredictable mild stress-induced depressive-like model mice through metabolomics and microbiota

Depression is a progressive neurodegenerative disease characterized by high prevalence, high suicide rate and high recurrence rate. In this study, the protein from Chlamydomonas reinhardtii was extracted and neutral protease hydrolysate (NPH) was obtained. Its in vitro MAO-A (Monoamine oxidase A) inhibitory activity and in vivo anti-depressive effects in chronic unpredictable mild stress (CUMS) model mice were investigated. The results demonstrated that NPH can improve depressive behaviour in CUMS model mice by elevating neurotransmitter levels and alleviating hippocampal tissue structure damage. The metabolomic analysis of brain and serum samples showed that their common metabolic pathways associated with anti-depressive effects are mainly alanine, aspartate, and glutamate metabolism, glycerophospholipid metabolism, tryptophan metabolism, and caffeine metabolism. Then, the gut microbiota analysis of feces indicated that 8 species with significant changes were associated with anti-depressive effects. Finally, 5 pairs of highly correlated metabolite-bacterium pairs were identified to modulate depressive behaviours. Taken together, the present data suggests that Chlamydomonas reinhardtii-derived hydrolysate could be used for development of functional foods with potential to improve depression.

Remimazolam ameliorates postoperative cognitive dysfunction after deep hypothermic circulatory arrest through HMGB1-TLR4-NF-κB pathway

BackgroundPostoperative cognitive dysfunction (POCD) is a complication of deep hypothermic circulatory arrest (DHCA). Various amounts of neurologic dysfunctions have been shown after DHCA, which has often been attributed to systemic inflammatory response syndrome and cerebral ischemia/reperfusion injury. Remimazolam is one of the commonly used anesthetic drugs with protective actions against inflammatory diseases, such as sepsis and cerebral ischemia/reperfusion injury. Here, we determined the protective effect and potential mechanism of action of remimazolam against neuronal damage after DHCA. MethodsA rat model of DHCA was established, and a gradient dosage of remimazolam was administered during cardiopulmonary bypass (CPB). The cognitive function of rats was evaluated by Morris water maze. Hematoxylin and eosin and TUNEL staining were performed to assess hippocampus tissue injury and neuronal apoptosis. Inflammatory cytokines concentration were analyzed by enzyme-linked immunosorbent assay. The protein expression was analyzed using automated electrophoresis western analysis and immunohistochemical analysis. ResultsThe appropriate dosage of remimazolam reduced histologic injury, neuronal apoptosis, microglia activation, and secondary inflammatory cascades, as well as the downregulation of the expression of the HMGB1-TLR4-NF-κB pathway after DHCA, improved the memory and learning abilities in DHCA rats. Further, administration of a TLR4 antagonist TAK-242 had a similar effect to remimazolam, while the TLR4 agonist LPS attenuated the effect of remimazolam. ConclusionsRemimazolam could ameliorate POCD after DHCA through the HMGB1-TLR4-NF-κB signaling pathway.

Autism-Related Cc2d1a Heterozygous Mice: Increased Levels of miRNAs Retained in DNA/RNA Hybrid Profiles (R-Loop).

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with a highly variable expression of phenotypes (restricted interest or activity and repetitive behavior in communication and social interactions), genes (mutation), markers (alteration of transcription) and pathways. Loss of function of the CC2D1A gene appears to primarily affect the brain, leading to a range of behavioral problems in humans. In our study published in 2020, we found that the expressions of miR-19a-3p, miR-361-5p, miR-150-5p, miR-3613-3p, miR-126-3p and miR-499a-5p were downregulated in the serum samples of autistic patients, their families and mouse models (Cc2d1a +/- and valproic acid treated males). Here, acquired non-Mendelian hereditary character in a genetically defined mouse model of autism (Cc2d1a +/-) correlates with the transcriptional alteration of five miRNAs. We seek to test the hypothesis that miRNA levels vary by changes in RNA/DNA structure during development, thereby creating transcription alteration and cell memory. Behavioral tests were conducted on the offspring of Cc2d1a (+/-) mutant and control mice, such as novel object, social interaction, marble burying and tail suspension behavior. Two RNA fractions were isolated from mouse hippocampal tissues and sperm cells via standard TRIzol extraction: free RNA and the fraction of RNA bound to DNA in the form of a DNA/RNA hybrid (R-loop). The expression levels of miR-19a-3p, miR-361-5p, miR-150-5p, miR-126-3p and miR-499a-5p were investigated by quantitative real-time RT-PCR. We report differences in the distribution of five miRNAs in the hippocampus between male and female mice, particularly in colonies of Cc2d1a (+/-) mice. Furthermore, the number of miRNAs engaged in the DNA/RNA hybrid fraction is generally higher in the mutant pedigree than in the control group. On the other hand, in sperm, both fractions are at lower levels than in controls. R-loops contribute to the physiology and pathology of organisms including human disease. Here, we report a variation in five miRNA levels between gender and tissue. Our results suggest that the transcription levels of these five miRNAs are directly regulated by their RNA.

Comparing the effect of high-intensity interval exercise and voluntary exercise training on cognitive functions in rats

It is known that exercise increases brain-derived neurotrophic factor (BDNF) levels in the hippocampus, the brain region responsible for learning and memory, resulting in improved cognitive functions and learning processes. However, it is claimed that different types of exercise cause different responses in the brain. It is thought that lactate and osteocalcin secreted in response to exercise are associated with an increase in BDNF levels. However, there are not enough studies on this subject. This study aimed to compare the effects of high-intensity interval training (HIIT) and voluntary exercise training on cognitive performance and molecular connections. Male rats were randomly divided into control, voluntary exercise training and HIIT groups. The voluntary exercise group had free access to the voluntary wheel for 8 weeks. The HIIT group performed HIIT on the treadmill 3 days a week for 8 weeks. The rats underwent open field (OF), elevated plus maze (EPM) and Morris water maze (MWM) tests 24 h after the last exercise training. Then, after blood was drawn under anesthesia, the rats were sacrificed and their hippocampus tissues were separated. Glucocorticoid and BDNF levels in the blood were evaluated by enzyme-linked immunosorbent assay (ELISA), and osteocalcin and BDNF expressions in the hippocampus were evaluated by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Neither voluntary exercise training nor HIIT had any significant effect on behavioral parameters assessed by OF, EPM and MWM tests. However, BDNF expression in hippocampus tissue was higher in the HIIT group than in the control group. In addition, osteocalcin expression in hippocampus tissue was higher in the HIIT and voluntary exercise groups than in the control group. In conclusion, according to the findings we obtained from this study, although it does not have a significant effect on cognitive functions, the effect of HIIT on brain functions seems to be more effective than voluntary exercise.

Diabetes and Cognitive Decline: An Innovative Approach to Analyzing the Biophysical and Vibrational Properties of the Hippocampus.

Diabetes Mellitus (DM) is a disease characterized by high blood glucose levels, known as hyperglycemia. Diabetes represents a risk factor for the development of neurodegenerative diseases, such as Alzheimer's Disease (AD), one of the most prevalent neurodegenerative diseases worldwide, which leads to progressive mental, behavioral, and functional decline, affecting many brain structures, especially the hippocampus. Here, we aim to characterize the ultrastructural, nanomechanical, and vibrational changes in hyperglycemic hippocampal tissue using atomic force microscopy (AFM) and Raman spectroscopy. DM was induced in rats by streptozotocin injection (type 1) or dietary intervention (type 2). Cryosections of the hippocampus were prepared and analyzed on an MM8 AFM (Bruker) in Peak Force Quantitative Nanomechanics mode, performing 25 μm2 scans in 9 regions of 3 samples from each group. Ultrastructural and nanomechanical data such as surface roughness, area, volume, Young's modulus, and adhesion were evaluated. The hippocampal samples were also analyzed on a T64000 Spectrometer (Horiba), using a laser λ = 632.8 nm, and for each sample, four spectra were obtained in different regions. AFM analyses show changes on the ultrastructural scale since diabetic animals had hippocampal tissue with greater roughness and volume. Meanwhile, diabetic tissues had decreased adhesion and Young's modulus compared to control tissues. These were corroboratedby Raman data that shows changes in the molecular composition of diabetic tissues. The individual spectra show that the most significant changes are in the amide, cholesterol, and lipid bands. Overall, the data presented here show that hyperglycemia induces biophysical alterations in the hippocampal tissue of diabetic rats, providing novel biophysical and vibrational cues on the relationship between hyperglycemia and dementia.

Investigating the influence of estrous cycle-dependent hormonal changes on neurogenesis in adult mice

ObjectiveNeurogenesis is the process of generating new neurons from neural stem cells (NSCs) in the adult brain. Sex hormones play an essential role in the development of the brain. The aim of this study was to evaluate the neurogenic changes in the brain at different phases of the estrous cycle in adult mice. Materials and methodsFemale NMRI mice were divided into four groups: 1- Estrous, 2- Proestrous, 3- Metestrous, and 4- Diestrous. Different stages of the estrous cycle were determined by staining of vaginal smears. The level of estrogen, progesterone, prolactin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) hormones was evaluated by the enzyme-linked immunosorbent assay (ELISA) method. The expression of brain-derived neurotrophic factor) BDNF), nerve growth factor (NGF), ciliary neurotrophic factor(CNTF)) genes in hippocampal and the expression of glial fibrillary acidic protein (GFAP) in subventricular zone (SVZ) tissue were evaluated. ResultsThe serum estrogen and FSH increased significantly in Proestrous group (p < 0.001). Also, progesterone and prolactin hormones were significantly increased in the Diaestrus group (p < 0.001). The expression levels of BDNF, NGF, and CNTF significantly increased in the hippocampal tissue of Proestrous and Diaestrus groups (p < 0.001). The number of GFAP+ cells in SVZ of the Proestrous and Diestrous groups had a significant increase (p < 0.05, p < 0.01, p < 0.001). ConclusionOur data showed that Changes in sex hormones, especially estrogen in the estrous cycle, can cause the production of new neurons and astrocytes in the hippocampus and SVZ. Therefore, the increase in neurotrophic factors in the Proestrus and Diestrus leads to neurogenesis in adult mice brains.

An integrated strategy for in-depth profiling of N-acylethanolamines in biological samples by UHPLC-HRMS

BackgroundN-acylethanolamines (NAEs) are a class of naturally occurring bioactive lipids that play crucial roles in various physiological processes, particularly exhibiting neuroprotective and anti-inflammatory properties. However, the comprehensive profiling of endogenous NAEs in complex biological matrices is challenging due to their low abundance, structural similarity and the limited availability of commercial standards. Here, we propose an integrated strategy for comprehensive profiling of NAEs that combines chemical derivatization and a three-dimensional (3D) prediction model based on quantitative structure-retention time relationship (QSRR) using liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS). ResultsAfter acetyl chloride (ACC) derivatization, the detection sensitivity of NAEs was significantly improved. We developed a QSRR prediction model to construct an in-house database for 141 NAEs, encompassing information on RT, MS1 (m/z), and MS/MS spectra. Propargylamine-labeled fatty acids were synthesized as RT calibrants across various analytical conditions to enhance the robustness of the RT prediction model. NAEs in biological samples were then in-depth profiled using parallel reaction monitoring (PRM) acquisition. This integrated strategy identified and annotated a total of 50 NAEs across serum, hippocampus and cortex tissues from a 5xFAD mouse model of Alzheimer's disease (AD). Notably, the levels of polyunsaturated NAEs, particularly NAE 20:5 and NAE 22:6, were significantly decreased in 5xFAD mice compared to WT mice, as confirmed by accurate quantitation using ACC-d0/d3 derivatization. SignificanceOur integrated strategy exhibits great potential for the in-depth profiling of NAEs in complex biological samples, facilitating the elucidation of NAE functions in diverse physiological and pathological processes.

Analysis of Brain Protein Stability Changes in a Mouse Model of Alzheimer's Disease.

The stability of proteins from rates of oxidation (SPROX), thermal proteome profiling (TPP), and limited proteolysis (LiP) techniques were used to profile the stability of ∼2500 proteins in hippocampus tissue cell lysates from 2- and 8-months-old wild-type (C57BL/6J; n = 7) and transgenic (5XFAD; n = 7) mice with five Alzheimer's disease (AD)-linked mutations. Approximately 200-500 protein hits with AD-related stability changes were detected by each technique at each age point. The hit overlap from technique to technique was low, and all of the techniques generated protein hits that were more numerous and largely different from those identified in protein expression level analyses, which were also performed here. The hit proteins identified by each technique were enriched in a number of the same pathways and biological processes, many with known connections to AD. The protein stability hits included 25 high-value conformation biomarkers with AD-related stability changes detected using at least 2 techniques at both age points. Also discovered were subunit- and age-specific AD-related stability changes in the proteasome, which had reduced function at both age points. The different folding stability profiles of the proteasome at the two age points are consistent with a different mechanism for proteasome dysfunction at the early and late stages of AD.

Dual-factor model of sleep and diet: a new approach to understanding central fatigue.

Numerous studies have recently examined the impact of dietary factors such as high-fat diets on fatigue. Our study aims to investigate whether high-fat diet (HFD) alone or combined with alternate-day fasting (ADF) can lead to the central fatigue symptoms and to investigate the potential integration of dietary and sleep variables in the development of central fatigue models. Seventy-five male Wistar rats were divided into five groups: control, HFD, HFD + ADF, modified multiple platform method (MMPM), and MMPM+HFD + ADF. Each group underwent a 21-day modeling period according to their respective protocol. Their behavioral characteristics, fatigue biochemical markers, hippocampal pathological changes, mitochondrial ultrastructure, and oxidative stress damage were analyzed. Our findings demonstrate that using only HFD did not cause central fatigue, but combining it with ADF did. This combination led to reduced exercise endurance, decreased locomotor activity, impaired learning and memory abilities, along with alterations in serum levels of alanine aminotransferase (ALT), creatine kinase (CK), and lactate (LAC), as well as hippocampal pathological damage and other central fatigue symptoms. Moreover, the MMPM+HFD + ADF method led to the most obvious central fatigue symptoms in rats, including a variety of behavioral changes, alterations in fatigue-related biochemical metabolic markers, prominent pathological changes in hippocampal tissue, severe damage to the ultrastructure of mitochondria in hippocampal regions, changes in neurotransmitters, and evident oxidative stress damage. Additionally, it was observed that rats subjected to HFD + ADF, MMPM, and MMPM+HFD + ADF modeling method exhibited significant brain oxidative stress damage. We have demonstrated the promotive role of dietary factors in the development of central fatigue and have successfully established a more stable and clinically relevant animal model of central fatigue by integrating dietary and sleep factors.

Anatomo-functional changes in neural substrates of cognitive memory in developmental amnesia: Insights from automated and manual Magnetic Resonance Imaging examinations.

Despite bilateral hippocampal damage dating to the perinatal or early childhood period and severely impaired episodic memory, patients with developmental amnesia continue to exhibit well-developed semantic memory across the developmental trajectory. Detailed information on the extent and focality of brain damage in these patients is needed to hypothesize about the neural substrate that supports their remarkable capacity for encoding and retrieval of semantic memory. In particular, we need to assess whether the residual hippocampal tissue is involved in this preservation, or whether the surrounding cortical areas reorganize to rescue aspects of these critical cognitive memory processes after early injury. We used voxel-based morphometry (VBM) analysis, automatic (FreeSurfer) and manual segmentation to characterize structural changes in the brain of an exceptionally large cohort of 23 patients with developmental amnesia in comparison with 32 control subjects. Both the VBM and the FreeSurfer analyses revealed severe structural alterations in the hippocampus and thalamus of patients with developmental amnesia. Milder damage was found in the amygdala, caudate, and parahippocampal gyrus. Manual segmentation demonstrated differences in the degree of atrophy of the hippocampal subregions in patients. The level of atrophy in CA-DG subregions and subicular complex was more than 40%, while the atrophy of the uncus was moderate (-24%). Anatomo-functional correlations were observed between the volumes of residual hippocampal subregions in patients and selective aspects of their cognitive performance, viz, intelligence, working memory, and verbal and visuospatial recall. Our findings suggest that in patients with developmental amnesia, cognitive processing is compromised as a function of the extent of atrophy in hippocampal subregions. More severe hippocampal damage may be more likely to promote structural and/or functional reorganization in areas connected to the hippocampus. In this hypothesis, different levels of hippocampal function may be rescued following this variable reorganization. Our findings document not only the extent, but also the limits of circuit reorganization occurring in the young brain after early bilateral hippocampal damage.