OBJECTIVES: To investigate the effects of hyperoxia on the expression of N-methyl-D-aspartate receptor 1 (NMDAR1) and its synapse-associated molecules, including cannabinoid receptor 1 (CB1R), postsynaptic density 95 (PSD95), and synapsin (SYN), in the hippocampus of neonatal rats. METHODS: One-day-old Sprague-Dawley neonatal rats were randomly divided into a hyperoxia group and a control group (n=8 per group). The hyperoxia group was exposed to 80% ± 5% oxygen continuously, while the control group was exposed to room air, for 7 days. At 1, 3, and 7 days after hyperoxia exposure, hematoxylin and eosin (HE) staining was used to observe histopathological changes in the brain. The expression levels of NMDAR1, CB1R, PSD95, and SYN proteins and mRNAs in the hippocampus were detected by immunohistochemistry, Western blotting, and quantitative real-time PCR. RESULTS: After 7 days of hyperoxia exposure, the hyperoxia group showed decreased neuronal density and disordered arrangement in brain tissue. Compared with the control group, after 1 day of hyperoxia exposure, CB1R mRNA and both NMDAR1 and CB1R protein expression in the hyperoxia group were significantly downregulated, while SYN protein expression was significantly upregulated (P<0.05). After 3 days, mRNA expression of NMDAR1, CB1R, and SYN was significantly decreased (P<0.05); NMDAR1 and CB1R protein expression was significantly downregulated (P<0.05), while PSD95 and SYN protein expression was significantly upregulated (P<0.05). After 7 days of hyperoxia, the protein expression of NMDAR1 and CB1R was significantly upregulated (P<0.05). CONCLUSIONS Continuous hyperoxia exposure induces time-dependent changes in the expression levels of NMDAR1 and its synapse-associated molecules in the hippocampus of neonatal rats.
Animals ; Receptors, N-Methyl-D-Aspartate/genetics* ; Rats, Sprague-Dawley ; Hippocampus/pathology* ; Rats ; Animals, Newborn ; Receptor, Cannabinoid, CB1/genetics* ; Hyperoxia/metabolism* ; Disks Large Homolog 4 Protein/genetics* ; Synapsins/genetics* ; Synapses ; Male ; Female ; RNA, Messenger/analysis*

OBJECTIVES: To determine the neuroprotective effects of berberine hydrochloride (BBR) against lead-induced injuries on the hippocampus of rats. METHODS: Wistar rats were exposed orally to doses of 100 and 500 ppm lead acetate for 1 and 2 months to develop subchronic and chronic lead poisening models, respectively. For treatment, BBR (50 mg/kg daily) was injected intraperitoneally to rats poisoned with lead. At the end of the experiment, the spatial learning and memory of rats were assessed using the Morris water maze test. Hippocampal tissue changes were examined by hematoxylin and eosin staining. The activity of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels as parameters of oxidative stress and antioxidant status of the hippocampus were evaluated. RESULTS: BBR reduced cognitive impairment in rats exposed to lead (P<0.05 or P<0.01). The resulting biochemical changes included a decrease in the activity of antioxidants and an increase in lipid peroxidation of the hippocampus of lead-exposed rats (P<0.05 or P<0.01), which were significantly modified by BBR (P<0.05). BBR also increased the density of healthy cells in the hippocampus of leadexposed rats (P<0.05). Significant changes in tissue morphology and biochemical factors of the hippocampus were observed in rats that received lead for 2 months (P<0.05). Most of these changes were insignificant in rats that received lead for 1 month. CONCLUSION BBR can improve oxidative tissue changes and hippocampal dysfunction in lead-exposed rats, which may be due to the strong antioxidant potential of BBR.
Animals ; Hippocampus/pathology* ; Rats, Wistar ; Antioxidants/pharmacology* ; Berberine/therapeutic use* ; Cognition/drug effects* ; Male ; Lead Poisoning/metabolism* ; Chronic Disease ; Oxidative Stress/drug effects* ; Maze Learning/drug effects* ; Rats ; Lipid Peroxidation/drug effects* ; Malondialdehyde/metabolism*

OBJECTIVE: To investigate the therapeutic effect of Xiangshao Granules (XSG) on post-stroke depression (PSD) and explore the underlying mechanisms. METHODS: Forty-three C57BL/6J mice were divided into 3 groups: sham (n=15), PSD+vehicle (n=14), and PSD+XSG (n=14) groups according to a random number table. The PSD models were constructed using chronic unpredictable mild stress (CUMS) after middle cerebral artery occlusion (MCAO). The sham group only experienced the same surgical operation, but without MACO and CUMS stimulation. The XSG group received XSG (60 mg/kg per day) by gavage for 4 weeks. The mice in the sham and vehicle groups were given the same volume of 0.9% saline at the same time. The body weight and behavior tests including open field test, sucrose preference test, tail suspension test, and elevated plus-maze test, were used to validate the PSD mouse model. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence staining were used to evaluate the anti-inflammatory effects of XSG. The potential molecular mechanisms were explored and verified through network pharmacology analysis, Nissl staining, Western blot, ELISA, and RT-qPCR, respectively. RESULTS: The body weight and behavior tests showed that MCAO combined with CUMS successfully established the PSD models. XSG alleviated neuronal damage, reduced the expressions of pro-apoptotic proteins Caspase-3 and B-cell lymphoma-2 (BCL-2)-associated X (BAX), and increased the expression of anti-apoptotic protein BCL-2 in PSD mice (P<0.05 or P<0.01). XSG inhibited microglial activation and the expressions of pro-inflammatory cytokines including tumor necrosis factor-α, interleukin (IL)-1 β, and IL-6 via the toll-like receptor 4/nuclear factor kappa-B signaling pathway in PSD mice (P<0.05 or P<0.01). Furthermore, XSG decreased the expression of indoleamine 2,3-dioxygenase1 (IDO1) and increased the concentration of 5-hydroxytryptamine in PSD mice (P<0.05 or P<0.01). CONCLUSION XSG could reverse the anxiety/depressionlike behaviors and reduce the neuronal injury in the hippocampus and prefrontal cortex of PSD mice, which may be a potential therapeutic agent for PSD.
Animals ; Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism* ; Depression/etiology* ; Drugs, Chinese Herbal/therapeutic use* ; Hippocampus/metabolism* ; Male ; Mice, Inbred C57BL ; Prefrontal Cortex/pathology* ; Microglia/metabolism* ; Stroke/drug therapy* ; Disease Models, Animal ; Mice ; Behavior, Animal/drug effects*

OBJECTIVE: To investigate the antidepressant effects of Xiaoyao Pill (XYP) by exploring its interactions with gut microbiota and tryptophan metabolism. METHODS: Utilizing network pharmacology, the functional substance groups, key targets, and pathways of XYP in the treatment of depression were identified. The chronic unpredictable mild stress (CUMS) protocol was implemented in male Sprague-Dawley rats to establish depression model. Thirty rats were randomly divided into 3 groups according to their body weight (10 for each): control, CUMS and XYP groups (1.8 g/kg). After 28-day interventions, behavioral phenotyping including sucrose preference test (SPT) and open field test (OFT) were performed. Biochemical validation encompassed enzyme-linked immunosorbent assay for serum cortisol, hematoxylin-eosin histopathology, and immunohistochemistry. Liquid chromatography-mass spectrometry was utilized to profile serum metabolites, while fecal samples underwent metagenomic sequencing for gut microbiota characterization. RESULTS: Network pharmacology studies predicted that key components can protect the nervous system by regulating inflammatory pathways through the blood-brain barrier. SPT and OFT showed that XYP treatment significantly ameliorated depressive-like behaviors (all P<0.05). XYP treatment also restored hippocampal neuronal density, increased serum neurotransmitter levels of neurotransmitters such as 5-hydroxytryptamine and vasoactive intestinal peptide, and while suppressing inflammatory markers such as tumor necrosis factor-alpha, interleukin-1 beta (IL-1 β), and IL-6 (all P<0.05). Metagenomics revealed significant restructuring of gut microbiota, notably the regulation of Parabacteroides distasonis (P<0.05). Non-targeted metabolomics analysis showed that the level of metabolites in the tryptophan and kynurenine pathway significantly changed (variable importance in the projection >1, P<0.05), and the change of metabolic flux was significantly correlated with behavioral improvement (P<0.05). CONCLUSIONS XYP exerts antidepressant effects by increasing neurotransmitter levels, reducing inflammatory makers and modulating Parabacteroides distasonis. Through further exploration of metabolomics, we found that XYP may play a protective role in depression by regulating tryptophan metabolism.
Animals ; Tryptophan/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Rats, Sprague-Dawley ; Depression/blood* ; Male ; Stress, Psychological/drug therapy* ; Behavior, Animal/drug effects* ; Rats ; Chronic Disease ; Hippocampus/drug effects*

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

OBJECTIVES: The integrated endoplasmic reticulum stress inhibitor (ISRIB) is a selective inhibitor of the protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway within endoplasmic reticulum stress (ERS) and can improve spatial and working memory in aged mice. Although ERS and oxidative stress are tightly interconnected, it remains unclear whether ISRIB alleviates cognitive impairment by restoring the balance between ERS and oxidative stress. This study aims to investigate the effects and mechanisms of ISRIB on lipopolysaccharide (LPS)-induced cognitive impairment in mice. METHODS: Eight-week-old male ICR mice were randomly divided into 3 groups: Normal saline (NS) group, LPS group, and ISRIB+LPS group. NS and LPS groups received daily intraperitoneal injections of normal saline for 7 days; on day 7, LPS group mice received intraperitoneal LPS (0.83 mg/kg) to establish a cognitive impairment model. ISRIB+LPS group received ISRIB (0.25 mg/kg) intraperitoneally for 7 days, with LPS injected 30 minutes after ISRIB on day 7. Cognitive ability was evaluated by the novel place recognition test (NPRT). Real-time fluorogenic quantitative PCR (RT-qPCR) was used to detect changes in nitric oxide synthase (NOS), superoxide dismutase-1 (SOD-1), and catalase (CAT) gene expression in the hippocampus and prefrontal cortex. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG), were measured in hippocampal and prefrontal cortex tissues. RESULTS: Compared with the NS group, mice in LPS group showed a significant reduction in novel place recognition ratio, upregulation of hippocampal NOS-1 and NOS-2 mRNA, downregulation of SOD-1 and CAT mRNA, increased MDA and GSSG, decreased GSH, and reduced GSH/GSSG ratio (all P<0.05). Compared with the LPS group, mice in ISRIB+LPS group exhibited significantly improved novel place recognition, downregulated NOS-1 and NOS-2 mRNA, upregulated SOD-1 and CAT mRNA, decreased MDA and GSSG, increased GSH, and an elevated GSH/GSSG ratio in the hippocampus (all P<0.05). No significant changes were observed in the prefrontal cortex. CONCLUSIONS ISRIB improves LPS-induced cognitive impairment in mice by restoring the oxidative/antioxidant balance in the hippocampus.
Animals ; Lipopolysaccharides ; Male ; Mice, Inbred ICR ; Cognitive Dysfunction/drug therapy* ; Mice ; Oxidative Stress/drug effects* ; Endoplasmic Reticulum Stress/drug effects* ; Hippocampus/drug effects* ; Nitric Oxide Synthase Type II/genetics* ; Guanidines/pharmacology* ; eIF-2 Kinase/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Superoxide Dismutase/metabolism*

Cognitive dysfunction often occurs in Alzheimer's disease, Parkinson's disease, cerebrovascular disease, or other neurodegenerative diseases, and can significantly impact the life quality of patients and create serious social, psychological, and economic burdens for individuals and their families. Numerous studies have confirmed that exercise can slow the decline in cognitive function through multiple pathways, in which fibronectin type III domain-containing protein 5 (FNDC5) plays an important role. However, the current research on the modulation of FNDC5 by exercise and its ability to improve hippocampal cognitive function lacks a systematic and comprehensive understanding. Therefore, this review focuses on the latest research progress regarding the role of exercise-induced FNDC5 in cognitive function, systematically reviews the positive effects of FNDC5 on cognitive function impairment caused by various factors, and clarifies the specific mechanisms by which exercise-induced FNDC5 improves cognitive function by inhibiting neuroinflammation and improving hippocampal neurogenesis and hippocampal synaptic plasticity. Based on the existing literature, we also identify the areas that require further research in this field. Overall, this review provides a theoretical basis for exercise-based prevention and improvement of cognitive function impairment.
Humans ; Cognition/physiology* ; Fibronectins/physiology* ; Exercise/physiology* ; Hippocampus/physiology* ; Cognitive Dysfunction/prevention & control* ; Neuronal Plasticity ; Animals ; Neurogenesis

OBJECTIVES: To explore the molecular mechanism by which miR-124 affects cognitive function of sleep-deprived rats. METHODS: Fifty-four adult male SD rats were randomized into 6 groups (n=9), including a normal control group, a sleep deprivation (SD) model group, and 4 intracerebral microinjection groups in which the rats were subjected to stereotactic injection of miR-124 agomir, miR-124 agomir NC, miR-124 antagomir, or miR-124 antagomir into the lateral ventricle 7 days before SD modeling. The cognitive functions of the rats were evaluated with Morris water maze test, and pathological changes in the hippocampus were observed using HE staining. The expression level of miR-124 in hippocampal tissues of the rats was detected with qRT-PCR, and the expression level of apoptosis-related proteins and signaling pathway proteins were determined using Western blotting. RESULTS: In Morris water maze test, the SD rat models treated with miR-124 agomir showed a significantly shorter escape latency and fewer platform crossings with increased percentage of time and swimming distance in the fourth quadrant as compared with those in SD model group, while the rats treated with miR-124 antagomir exhibited worsened performance in the test. In the SD rat models, treatment with miR-124 agomir obviously lessened pathological changes in the hippocampus, while treatment with miR-124 antagomir significantly worsened the pathological changes. Compared with those in SD model group, the miR-124 agomir-treated rats showed an increased hippocampal expression of miR-124 with upregulated protein expressions of PI3K, p-AKT/AKT, and Bcl-2 and downregulated expressions of Bax and caspase-3 proteins, while rats treated with miR-124 antagomir showed significantly decreased hippocampal expression of miR-124 with lowered expressions of PI3K, p-AKT/AKT and Bcl-2 proteins and increased Bax and caspase-3 protein expressions. CONCLUSIONS High expression of miR-124 alleviates SD-induced cognitive decline and neuronal apoptosis in rats by activating the PI3K/AKT signaling pathway.
Animals ; MicroRNAs/metabolism* ; Signal Transduction ; Proto-Oncogene Proteins c-akt/metabolism* ; Male ; Rats, Sprague-Dawley ; Hippocampus/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Cognition ; Rats ; Sleep Deprivation/metabolism* ; Apoptosis ; Maze Learning

OBJECTIVES: To explore the bioactive components in Jiawei Xiaoyao Pills (JWXYP) and their mechanisms for alleviating depression-like behaviors. METHODS: The active compounds, key targets, and pathways of JWXYP were identified using TCMSP and TCMIP databases. Thirty-six SD rats were randomized equally into 6 groups including a control group and 5 chronic unpredictable mild stress (CUMS)-induced depression groups. After modeling, the 5 model groups were treated with daily gavage of normal saline, 1.8 mg/kg fluoxetine hydrochloride (positive control drug), or JWXYP at 1.44, 2.88, and 4.32 g/kg. The depression-like behaviors of the rats were evaluated using behavioral tests, and pathological changes in the liver and hippocampus were examined with HE staining. The biochemical indicators in the serum and brain tissues were detected using ELISA. Serum metabolomics analysis was performed to identify the differential metabolites using OPLS-DA, and gut microbiota changes were analyzed using 16S rDNA sequencing. RESULTS: Network pharmacology revealed that menthone and paeonol in JWXYP were capable of penetrating the blood-brain barrier to regulate inflammatory pathways and protect the nervous system. In the rat models subjected to CUMS, treatment with JWXYP significantly improved body weight loss, sucrose preference and open field activities, reduced liver inflammation, alleviated structural changes in the hippocampal neurons, decreased serum levels of TNF‑α, IL-1β, IL-6 and LBP, and increased 5-HT and VIP concentrations in the serum and brain tissue, and these effects were the most pronounced in the high-dose group. Metabolomics analysis showed changes in such metabolites as indole-3-acetamide and acetyl-L-carnitine in JWXYP-treated rats, involving the pathways for bile acid biosynthesis and amino acid metabolism. 16S rDNA analysis demonstrated increased gut microbiota diversity and increased abundance of Lactobacillus species in JWXYP-treated rats. CONCLUSIONS JWXYP alleviates depression-like symptoms in rats by regulating the neurotransmitters, inhibiting inflammation and oxidation, and modulating gut microbiota.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Neurotransmitter Agents/metabolism* ; Rats ; Inflammation ; Male ; Hippocampus ; Behavior, Animal/drug effects*

OBJECTIVES: To investigate the effects of periodontitis induced by Prevotella nigrescens (Pn) combined with ligation on cognitive functions in mice. METHODS: Twenty-four C57BL/6J mice were randomly divided into control group, ligation group, and ligation + Pn treatment (P+Pn) group. Experimental periodontitis was induced by silk ligation of the first molars followed by topical application of Pn for 6 weeks. After modeling, alveolar bone resorption was assessed using micro-CT and histological analysis. Learning and memory abilities of the mice were evaluated using open field test (OFT), novel object recognition test (NORT), and Morris water maze test (MWM). Seven weeks after the start of modeling, the mice were sacrificed for examining histopathological changes in the hippocampus using HE and Nissl staining. RESULTS: After 6 weeks of molar ligation, micro-CT revealed horizontal alveolar bone resorption and furcation exposure in the mice, and histological analysis showed apical migration of the junctional epithelium, epithelial ridge hyperplasia, and lymphocyte infiltration, and these changes were obviously worsened in P+Pn group. Alveolar bone height decreased significantly in both ligation groups compared to the control group. Cognitive tests showed that the mice in both of the ligation groups traveled shorter distances in OFT, showed reduced novel object preference in NORT, and exhibited longer escape latencies in MWM, and the mice in P+Pn group had significantly poorer performances in the tests. Histologically, obvious neuronal cytoplasmic degeneration, necrosis, nuclear pyknosis, vacuolation, and reduced Nissl bodies and viable neurons were observed in the hippocampal regions of the mice in the two ligation groups. CONCLUSIONS Pn infection aggravates alveolar bone destruction, accelerates necrosis and causes morphological abnormalities of neuronal cells in the hippocampus to reduce cognitive functions of mice with periodontitis.
Animals ; Periodontitis/microbiology* ; Mice ; Mice, Inbred C57BL ; Cognition ; Alveolar Bone Loss ; Hippocampus/pathology* ; Male ; Inflammation ; Maze Learning