Alzheimer's disease(AD),a neurodegenera-tive disorder with complex etiologies,manifests through a cascade of pathological changes before clinical symptoms become apparent.Among these early changes,alterations in t...Alzheimer's disease(AD),a neurodegenera-tive disorder with complex etiologies,manifests through a cascade of pathological changes before clinical symptoms become apparent.Among these early changes,alterations in the expression of non-coding RNAs(ncRNAs)have emerged as pivotal events.In this study,we focused on the aber-rant expression of ncRNAs and revealed that Lamrl-ps1,a pseudogene of the laminin receptor,significantly exac-erbates early spatial learning and memory deficits in APP/PS1 mice.Through a combination of bioinformatics pre-diction and experimental validation,we identified the miR-29c/Bacel pathway as a potential regulatory mechanism by which Lamrl-ps1 influences AD pathology.Importantly,augmenting the miR-29c-3p levels in mice ameliorated memory deficits,underscoring the therapeutic potential of targeting miR-29c-3p in early AD intervention.This study not only provides new insights into the role of pseudogenes in AD but also consolidates a foundational basis for consid-ering miR-29c as a viable therapeutic target,offering a novel avenue for AD research and treatment strategies.展开更多
Objective Chronic lead （Pb） exposure during development is known to produce learning deficits. Nitric oxide participates in the synaptic mechanisms involved in certain forms of learning and memory. This study was de...Objective Chronic lead （Pb） exposure during development is known to produce learning deficits. Nitric oxide participates in the synaptic mechanisms involved in certain forms of learning and memory. This study was designed to clarify whether Pb-induced impairment in learning and memory was associated with the changes of nitric oxide levels in mice brains. Methods Sixty Balb/c mice aged l0 days were chosen. A model of lead exposure was established by drinking 0.025%, 0.05% 0.075% lead acetate, respectively for 8 weeks. The controls were orally given distilled water. The ability to learn and memorize was examined by open field test, T-water maze test. In parallel with the behavioral data, NO level of hippocampus tissue was detected by biochemical assay. Results Compared with control groups, （1） the weight of 0.075% group was significantly reduced （P〈0.05）; （2） The number of times in mice attaining the required standards in T-water maze test was lower in 0.075% group （P〈0.01）. No significant difference was found between experimental and control groups in open field test （P〉0.05）; （3） NO level of mouse hippocampus tissue was decreased in 0.075% group （P〈0.01）. Conclusions The findings suggest that decreased hippocampus NO level may contribute to the Pb-induced deficits in learning and memory processes.展开更多
OBJECTIVE To investigate the effects of imperatorin on the spatial learning memory impairment and neuroinflammation in model mice of Alzheimer disease(AD)induced by intracerebroventricular injection of Aβ1-42.METHODS...OBJECTIVE To investigate the effects of imperatorin on the spatial learning memory impairment and neuroinflammation in model mice of Alzheimer disease(AD)induced by intracerebroventricular injection of Aβ1-42.METHODS Mouse model of AD was established by injection of Aβ1-42 into the lateral ventricles.Im⁃peratorin(2.5 and 5.0 mg·kg-1,daily)was inject⁃ed by intraperitoneally 1 h after intracerebroven⁃tricular injection for 13 d.The effect of imperato⁃rin on the spatial learning and memory impair⁃ment was assessed by eight arm maze tests.The levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in mouse cortex and hip⁃pocampus were detected by ELISA.The protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK were detected by Western blotting.RESULTS As compared with the AD model group,imperatorin treatment significantly attenuated Aβ1-42-induced spatial learning and memory impairment assessed by eight arm maze tests.In addition,imperatorin significantly reduced the levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in the cerebral cortex and hippocampus.Meanwhile,Western blotting results showed that imperatorin treat⁃ment significantly down-regulated the protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK.CONCLUSION Imperatorin has neuroprotective effects in the Aβ1-42 induced AD model mice and its mechanism may be partially associated with the inhibition of inflam⁃matory response in the cortex and hippocampus.展开更多
Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life ...Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.展开更多
Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However...Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However,the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood.Here,using mice in which astrocytic endothelin-1 was overexpressed,we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia(1 hour of ischemia;7 days,28 days,or 3 months of reperfusion).We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion.Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6,which were differentially expressed in the brain,were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke.Moreover,the levels of the enriched differentially expressed proteins were closely related to lipid metabolism,as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis.Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine,sphingomyelin,and phosphatidic acid.Overall,this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.展开更多
Recent genome studies indicate that tree shrew is in the order or a closest sister of primates,and thus may be one of the best animals to model human diseases.In this paper,we report on a social defeat model of depres...Recent genome studies indicate that tree shrew is in the order or a closest sister of primates,and thus may be one of the best animals to model human diseases.In this paper,we report on a social defeat model of depression in tree shrew（Tupaia belangeri chinensis）.Two male tree shrews were housed in a pair-cage consisting of two independent cages separated by a wire mesh partition with a door connecting the two cages.After one week adaptation,the connecting door was opened and a brief fighting occurs between the two male tree shrews and this social conflict session consisted of 1 h direct conflict（fighting） and 23 h indirect influence（e.g.smell,visual cues） per day for 21 days.The defeated tree shrew was considered the subordinate.Compared with na？ve animals,subordinate tree shrews at the final week of social conflict session showed alterations in body weight,locomotion,avoidance behavior and urinary cortisol levels.Remarkably,these alterations persisted for over two weeks.We also report on a novel captive conditioning model of learning and memory in tree shrew.An automatic trapping cage was placed in a small closed room with a freely-moving tree shrew.For the first four trials,the tree shrew was not trapped when it entered the cage and ate the bait apple,but it was trapped and kept in the cage for 1 h on the fifth trial.Latency was defined as the time between release of the tree shrew and when it entered the captive cage.Latencies during the five trials indicated adaptation.A test trial 24 h later was used to measure whether the one-trial trapping during the fifth trial could form captive memory.Tree shrews showed much longer trapping latencies in the test trial than the adaptation trials.The N-methyl-d-aspartate（NMDA） receptor antagonist MK-801（0.2 mg/kg,i.p.）,known to prevent the formation of memory,did not affect latencies in the adaptation trails,but did block captive memory as it led to much shorter trapping latencies compared to saline treatment in the test trial.These results demonstrate a chronic social defeat model of depression and a novel one-trial captive conditioning model for learning and memory in tree shrews,which are important for mechanism studies of depression,learning,memory,and preclinical evaluation for new antidepressants.展开更多
Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of lear...Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of learning and memory after TBI, and to investigate the mechanism of the protective effect of NMDA receptor antagonist MK-801 on learning and memory disorder after TBI. Methods Forty Sprague-Dawley rats （weighing approximately 200 g） were randomized into 5 groups （n = 8 in each group）： control group, model group, low-dose group （MK-801 0.5 mg/kg）, middle-dose group （MK-801 2 mg/kg）, and high-dose group （MK-801 10 mg/kg）. TBI model was established using a weight-drop head injury mode. After 2-month drug treatment, learning and memory ability was evaluated by using Morris water maze test. Then the animals were sacrificed, and brain tissues were taken out for morphological and immunohistochemical assays. Results The ability of learning and memory was significantly impaired in the TBI model animals. Besides, the neuronal caspase-3 expression, neuronal nitric oxide synthase （nNOS）-positive neurons and OX-42-positive microglia were all increased in TBI animals. Meanwhile, the number of neuron synapses was decreased, and vacuoles degeneration could be observed in mitochondria. After MK-801 treatment at 3 different dosages, the ability of learning and memory was markedly improved, as compared to that of the TBI model animals. Moreover, neuronal caspase-3 expression, OX-42-positive microglia and nNOS-positive neurons were all significantly decreased. Meanwhile, the mitochondria degeneration was greatly inhibited. Conclusion MK-801 could significantly inhibit the degeneration and apoptosis of neurons in damaged brain areas. It could also inhibit TBI-induced increase in nNOS-positive neurons and OX-42-positive microglia. Impairment in learning and memory in TBI animals could be repaired by treatment with MK-801.展开更多
Objective To investigate whether estrogen modulates learning and memory and long-term potentiation （LTP） in the hippocampus of rats with Alzheimer＇s disease （AD）. Methods The rats were divided into ovariectomy （...Objective To investigate whether estrogen modulates learning and memory and long-term potentiation （LTP） in the hippocampus of rats with Alzheimer＇s disease （AD）. Methods The rats were divided into ovariectomy （OVX） and estrogen replacement therapy （ERT） groups. Rats in the ERT group received OVX, followed by ERT, while rats in the OVX group received only OVX. The rat model of AD was established by injection of 1 μL （10 μg/μL） amyloid-beta peptide 1-40（Aβ1-40） into the hippocampus. The learning and memory ability and LTP were determined by Morris water maze and electrophysiological method, respectively. Results The escape latency in Morris water maze significantly decreased in ERT group compared with that in OVX group （P 〈 0.05）. Besides, rats in ERT group exhibited a significant enhancement of the magnitude of LTP at 30 min after high-frequency stimulation （HFS）, compared with that in OVX group （P 〈 0.01）. Conclusion ERT can attenuate the cognitive deficits in the rat model of AD, and estrogen can regulate LTP and synaptic remodeling in AD rats.展开更多
BACKGROUND： The present study analyzed the effect of 3 days （2 h/d） intrauterine hypoxia on learning and memory in juvenile rats, as well as the therapeutic effects of Angelica sinensis on dentate gyrus neurons, as...BACKGROUND： The present study analyzed the effect of 3 days （2 h/d） intrauterine hypoxia on learning and memory in juvenile rats, as well as the therapeutic effects of Angelica sinensis on dentate gyrus neurons, as well as learning and memory. OBJECTIVE： To explore the effects of intrauterine hypoxia on hippocampal dentate gyrus neurons, as well as learning and memory, in juvenile rats; to explore N-methyI-D-aspartate receptor-1 （NMDAR1） expression in the dentate gyrus of neonatal rats following intrauterine hypoxia, as well as prolonged hypoxia; to investigate the regulatory mechanisms of Angelica sinensis. DESIGN, TIME AND SETTING： A randomized and controlled experiment based on developmental neurobiology was performed at the Department of Histology and Embryology in Luzhou Medical College from October 2007 to October 2008. MATERIALS： Angelica sinensis solution （250 g/L） was obtained from Central South Hospital of Wuhan University, China. Neuron-specific enolase and NMDAR1 mRNA in situ hybridization reagents were provided by Wuhan Boster Biological Technology, China. Image-Pro Plus 6.0 analysis system was purchased from Media Cybernetics, USA. METHODS： Healthy pregnant Sprague Dawley rats （n = 30） were randomly divided into control （n = 10）, hypoxia （n = 10）, and Angelica （n = 10） groups. The Angelica and hypoxia pregnant rats were placed in a three-gas incubator （oxygen concentration： 13%） starting with day 14 of pregnancy for 2 hours/day for 5 consecutive days to establish a fetal rat intrauterine hypoxia model. One hour prior to modeling, the pregnant rats from the Angelica and hypoxia groups received Angelica sinensis and normal saline （8 mL/kg） injections, respectively, through the caudal vein. The control group procedures were identical to the hypoxia group, but lacked the hypoxic conditions. MAIN OUTCOME MEASURES： Brain tissues of neonatal rats were used to detect expression of NMDAR1 mRNA, and brain tissues of juvenile rats aged 30 days were used to determine neuron-specific enolase mRNA expression by in situ hybridization. Microscopic images （400x） of the hippocampal dentate gyrus were collected. The integral optical density （IOD） value of positive NMDAR1 mRNA cells in the dentate gyrus of neonatal rats, as well as the quantity and the IOD value of positive neuron-specific enolase mRNA cells in the dentate gyrus of juvenile rats, were analyzed with Image-Pro IPP6.0 software. At 30 days after birth, learning and memory parameters were measured in the juvenile rats using Morris water maze. RESULTS： The quantity and the IOD value of positive neuron-specific enolase mRNA cells in the dentate gyrus of the hypoxia group juvenile rats were significantly less than the control group （P 〈 0.05）, and also less than the Angelica group （P 〈 0.05）. The IOD value of positive NMDAR1 mRNA cells in the dentate gyrus of the hypoxia group neonatal rats was significantly greater than the control group, and also greater than the Angelica group （P 〈 0.05）. In the Morris water maze, the searching time during the probe trial and reversal probe trial was shorter in the hypoxia group juvenile rats compared with the control group, and the Angelica group was prolonged compared with the hypoxia group （P 〈 0.05）. CONCLUSION： Intrauterine hypoxia increased expression of NMDAR1 mRNA in the dentate gyrus of neonatal rats, reduced the number of dentate gyrus neurons, and negatively affected learning and memory in juvenile rats. In contrast, Angelica sinensis injection improved the intrauterine hypoxic condition, increased the number of dentate gyrus neurons, and improved the learning and memory deficits of the juvenile rats.展开更多
The present study was designed to determine microtubule-associated protein-2 and synaptophysin expression in the hippocampal CA3 region in a rat model of middle cerebral artery occlusion. The rats were treated with ac...The present study was designed to determine microtubule-associated protein-2 and synaptophysin expression in the hippocampal CA3 region in a rat model of middle cerebral artery occlusion. The rats were treated with acupuncture at Baihui （GV 20）, Qubin （GB 7）, and Qianding （GV 21） points, in addition to exercise training. Results were compared with rats undergoing exercise training only. The Y-maze method and immunohistochemistry revealed decreased error frequency of passing through Y-maze, as well as significantly increased microtubule-associated protein-2 and synaptophysin expression, in the acupuncture with exercise training group compared with the model and exercise training groups after 5 weeks. Microtubule-associated protein-2 and synaptophysin expressions negatively correlated with error frequency of passing through the Y-maze. These results suggested that acupuncture combined with exercise training improved learning and memory functions in a rat model of cerebral infarction. The mechanisms of action were hypothesized to be associated with dendritic or synaptic plasticity in the ipsilateral hippocampal CA3 region.展开更多
BACKGROUND： Presently, clinic memory scale is used to evaluate learning memory ability in most studies, and the influence of difference in measurement condition of individuals exists. OBJECTIVE： To study the correla...BACKGROUND： Presently, clinic memory scale is used to evaluate learning memory ability in most studies, and the influence of difference in measurement condition of individuals exists. OBJECTIVE： To study the correlation between regional cerebral blood flow （rCBF） perfusion and learning memory function in special brain regions of patients with cerebral infarction at convalescent period, and to try to find out a method which can quantitatively evaluate learning ability. DESIGN： Case observation, and correlation analysis. SETTINGS： Shandong Institute for Behavioral Medicine; the Affiliated Hospital of Jining Medical College. PARTICIPANTS： Totally 70 patients with cerebral infarction admitted to Department of Neurology, Jining Medical College between January 2004 and December 2005 were involved. The involved patients, 58 male and 12 female, were averaged （52±3） years, and they were all right handed. They all met the diagnosis criteria instituted by the Fourth National Conference on Cerebrovascular Disease, and were confirmed as cerebral infarction by skull CT or MRI. Informed consents of detected items were obtained from all the patients and relatives. METHODS： When the patients were at convalescent period, their learning and memory ability were measured with “ clinic memory scale （set A）”. The 18 patients whose total mark over 100 were regarded as good learning memory function group; The 23 cases whose total mark less than 70 were regarded as poor learning memory function group. RCBF of hippocampus, nucleus amygdalae, temporal cortex and prefrontal lobe of patients between two groups were measured and compared by single photon emission computed tomography （SPECT）. The total scores of the 18 good learning memory patients and 23 poor learning memory patients were taken as dependent variable Y, and their rCBFs of hippocampus, nucleus amygdale, temporal cortex and prefrontal lobe respectively as independent variable X for linear correlation analysis. MAIN OUTCOME MEASURES： Correlation of rCBF in different brain regions and learning memory ability in patients with cerebral infarction. RESULTS： ①The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of good learning memory function group were significantly higher than those of poor learning memory function group （P 〈 0.05）. ②In the good learning memory function group, rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex were significantly positively correlated with memory scale scores （ r = 0.961, 0.926, 0.954, 0.907, P 〈 0.05 ） , and also in the poor learning memory function group （r = 0.979, 0.976, 0.991, 0.953, P 〈 0.05 ） . CONCLUSION： The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of patients with cerebral infarction are significantly positively correlated with memory scale scores. Predicting learning memory ability of patients by quantitative determination of rCBF provides a quantitative and objective method for evaluating learning memory ability.展开更多
Microglia are the resident macrophages of the central nervous system.Microglia possess varied morphologies and functions.Under normal physiological conditions,microglia mainly exist in a resting state and constantly m...Microglia are the resident macrophages of the central nervous system.Microglia possess varied morphologies and functions.Under normal physiological conditions,microglia mainly exist in a resting state and constantly monitor their microenvironment and survey neuronal and synaptic activity.Through the C1 q,C3 and CR3"Eat Me"and CD47 and SIRPα"Don't Eat Me"complement pathways,as well as other pathways such as CX3 CR1 signaling,resting microglia regulate synaptic pruning,a process crucial for the promotion of synapse formation and the regulation of neuronal activity and synaptic plasticity.By mediating synaptic pruning,resting microglia play an important role in the regulation of experience-dependent plasticity in the barrel cortex and visual cortex after whisker removal or monocular deprivation,and also in the regulation of learning and memory,including the modulation of memory strength,forgetfulness,and memory quality.As a response to brain injury,infection or neuroinflammation,microglia become activated and increase in number.Activated microglia change to an amoeboid shape,migrate to sites of inflammation and secrete proteins such as cytokines,chemokines and reactive oxygen species.These molecules released by microglia can lead to synaptic plasticity and learning and memory deficits associated with aging,Alzheimer's disease,traumatic brain injury,HIV-associated neurocognitive disorder,and other neurological or mental disorders such as autism,depression and post-traumatic stress disorder.With a focus mainly on recently published literature,here we reviewed the studies investigating the role of resting microglia in synaptic plasticity and learning and memory,as well as how activated microglia modulate disease-related plasticity and learning and memory deficits.By summarizing the function of microglia in these processes,we aim to provide an overview of microglia regulation of synaptic plasticity and learning and memory,and to discuss the possibility of microglia manipulation as a therapeutic to ameliorate cognitive deficits associated with aging,Alzheimer's disease,traumatic brain injury,HIV-associated neurocognitive disorder,and mental disorders.展开更多
The present study was aimed at determining the effects of Tongqiao Huoxue Decoction （TQHXD） on the Ca2＋-CaMKII-CREB pathway and the memory and learning capacities of rats with vascular dementia （VD）. The rat VD m...The present study was aimed at determining the effects of Tongqiao Huoxue Decoction （TQHXD） on the Ca2＋-CaMKII-CREB pathway and the memory and learning capacities of rats with vascular dementia （VD）. The rat VD model was established by using an improved bilateral carotid artery ligation method. The Morris water maze experiment was used to evaluate the ethology of the VD rats following treatments with TQHXD at 3.01, 6.02, and 12.04 g.kg-1 per day for 31 days. At the end of experiment, the hippocampus were harvested and analyzed. Western blotting and RT-PCR were used to measure the expression levels of calmodulin-binding protein kinase II（CaMKII）, protein kinase A（PKA）, cAMP-response element binding protein（CREB）, and three N-methyl-D-aspart^c acid receptor subunits （NR1, NR2A, and NR2B）. Our results revealed that TQHXD could alleviate the loss of learning abilities and increase the memory capacity （P 〈 0.05 and P 〈 0.01 vs the model group, respectively）. The treatment with 6.02 and 12.04 g.kg-1 of TQHXD significantly up-regulated the Ca2＋-CaMKII-CREB pathway in the hippocampus. In conclusion, TQHXD showed therapeutic effects on a bilateral carotid artery ligation-induced vascular dementia model, through the up-regulation of calcium signalling oathwavs.展开更多
Objective To explore the effects of exercise on dentate gyrus （DG） neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrabippocampal ...Objective To explore the effects of exercise on dentate gyrus （DG） neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrabippocampal microinjection of kainic acid （KA）. Bromodeoxyuridine （BrdU） was used to label dividing cells. Y maze test was used to evaluate the ability of learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity： lightly running, moderately running, or heavily running. Results Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number （EN） in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. Conclusion Moderate exercise could enhance the DG neurogenesis and ameliorate the ability of learning and memory in hippocampus-lesioned rats.展开更多
With key roles in essential brain functions ranging from the long-term potentiation(LTP) to synaptic plasticity,the N-methyl-D-aspartic acid receptor(NMDAR) can be considered as one of the fundamental glutamate recept...With key roles in essential brain functions ranging from the long-term potentiation(LTP) to synaptic plasticity,the N-methyl-D-aspartic acid receptor(NMDAR) can be considered as one of the fundamental glutamate receptors in the central nervous system.The role of NMDA R was first identified in synaptic plasticity and has been extensively studied.Some molecules,such as Ca^(2+),postsynaptic density 95(PSD-95),calcium/calmodulin-dependent protein kinase II(Ca MK II),protein kinase A(PKA),mitogen-activated protein kinase(MAPK) and cyclic adenosine monophosphate(c AMP) responsive element binding protein(CREB),are of special importance in learning and memory.This review mainly focused on the new research of key molecules connected with learning and memory,which played important roles in the NMDAR signaling pathway.展开更多
Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clin...Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clinical symptoms and delay the progression of Alzheimer＇s disease. The present study replicated a rat model of aging induced by injecting quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of eleutheroside B or E （50, 100, 200 mg/kg）, and rats injected with Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose eleutheroside B or E. Hematoxylin-eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced cholinesterase activity, and dose-dependent increases in acetylcholine content and decreases in choline content following eleutheroside B or E treatment, similar to those seen in the Huperzine A group. These findings indicate that eleutheroside B or E improves learning and memory in aged rats. These effects of eleutheroside B or E may be mediated by activation of cholinesterase or enhanced reuse of choline to accelerate the synthesis of acetylcholine in hippocampal neurons.展开更多
Nitric oxide （NO） is a novel type of neurotransmitter that is closely associated with synaptic plasticity, learning and memory. In the present study, we assessed the effects of Larginine and NnitroL arginine methyle...Nitric oxide （NO） is a novel type of neurotransmitter that is closely associated with synaptic plasticity, learning and memory. In the present study, we assessed the effects of Larginine and NnitroL arginine methylester （LNAME, a nitric oxide synthase inhibitor） on learning and memory. Rats were assigned to three groups receiving intracerebroventricular injections of LArg （the NO precursor）, LNAME, or 0.9% NaCI （control）, once daily for seven con secutive days. Twelve hours after the last injection, they underwent an electric shockpaired Y maze test. Twentyfour hours later, the rats＇ memory of the safe illuminated arm was tested. After that, the levels of NO and a7 nicotinic acetylcholine receptor （a7 nAChR） in the prefrontal cortex and hippocampus were assessed using an NO assay kit, and immunohistochemistry and Western blots, respectively. We found that, compared to controls, LArgtreated rats received fewer foot shocks and made fewer errors to reach the learning criterion, and made fewer errors during the memorytesting session. In contrast, LNAMEtreated rats received more foot shocks and made more errors than controls to reach the learning criterion, and made more errors during the memorytesting session. In parallel, NO content in the prefrontal cortex and hippocampus was higher in LArgtreated rats and lower inLNAME rats, compared to controls. Similarly, （]7 nAChR immunoreactivity and protein expression in the prefrontal cortex and hippocampus were higher in LArgtreated rats and lower in LNAME rats, compared to controls. These results suggest that the modulation of NO content in the brain correlates with a7 nAChR distribution and expression in the prefrontal cortex and hippocampus, as well as with learning and memory performance in the Ymaze.展开更多
BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheime...BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.展开更多
Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extrac...Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extracts may dose-dependently inhibit non-enzymatic saccharification in vitro. This study aimed to examine the effect of Radix Achyranthis Bidentatae on advanced glycation end products and on learning and memory capabilities in ovariectomized rats. Ovariectomized rats were treated with Radix Achyranthis Bidentatae alcohol extracts （containing 1.5 g/kg crude drug） or 0.1% aminoguanidine for 12 weeks and behavioral testing was performed with the Y-electrical maze. This test revealed that Radix Achyranthis Bidentatae and aminoguanidine could improve the learning and memory capabilities of ovariectomized rats. Results of competitive enzyme-linked immunosorbent assay showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine reduced the accumulation of advanced glycation end products in the frontal cortex of ovariectomized rats, while increasing content in the blood and urine. Biochemical tests showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine decreased superoxide dismutase activity in the serum and frontal cortex, and increased serum levels of glutathione peroxidase in ovariectomized rats. In addition there was no apparent effect on malondialdehyde levels. These experimental findings indicate that Radix Achyranthis Bidentatae inhibits production of advanced glycation end products and its accumulation in brain tissue, and improves learning and memory capabilities in ovariectomized rats. These effects may be associated with an anti-oxidative action of the extract.展开更多
基金supported by a Cooperation Project of Nanchong Science and Technology(22SXZRKX0016)the Research Development Fund of North Sichuan Medical College(CBY21-QD24)+2 种基金the Sichuan Science and Technology Program(2022NSFSC1472)the National Natural Science Foundation of China(32200795)the Natural Science Foundation of Hubei Province(2022CFB608).
文摘Alzheimer's disease(AD),a neurodegenera-tive disorder with complex etiologies,manifests through a cascade of pathological changes before clinical symptoms become apparent.Among these early changes,alterations in the expression of non-coding RNAs(ncRNAs)have emerged as pivotal events.In this study,we focused on the aber-rant expression of ncRNAs and revealed that Lamrl-ps1,a pseudogene of the laminin receptor,significantly exac-erbates early spatial learning and memory deficits in APP/PS1 mice.Through a combination of bioinformatics pre-diction and experimental validation,we identified the miR-29c/Bacel pathway as a potential regulatory mechanism by which Lamrl-ps1 influences AD pathology.Importantly,augmenting the miR-29c-3p levels in mice ameliorated memory deficits,underscoring the therapeutic potential of targeting miR-29c-3p in early AD intervention.This study not only provides new insights into the role of pseudogenes in AD but also consolidates a foundational basis for consid-ering miR-29c as a viable therapeutic target,offering a novel avenue for AD research and treatment strategies.
文摘Objective Chronic lead （Pb） exposure during development is known to produce learning deficits. Nitric oxide participates in the synaptic mechanisms involved in certain forms of learning and memory. This study was designed to clarify whether Pb-induced impairment in learning and memory was associated with the changes of nitric oxide levels in mice brains. Methods Sixty Balb/c mice aged l0 days were chosen. A model of lead exposure was established by drinking 0.025%, 0.05% 0.075% lead acetate, respectively for 8 weeks. The controls were orally given distilled water. The ability to learn and memorize was examined by open field test, T-water maze test. In parallel with the behavioral data, NO level of hippocampus tissue was detected by biochemical assay. Results Compared with control groups, （1） the weight of 0.075% group was significantly reduced （P〈0.05）; （2） The number of times in mice attaining the required standards in T-water maze test was lower in 0.075% group （P〈0.01）. No significant difference was found between experimental and control groups in open field test （P〉0.05）; （3） NO level of mouse hippocampus tissue was decreased in 0.075% group （P〈0.01）. Conclusions The findings suggest that decreased hippocampus NO level may contribute to the Pb-induced deficits in learning and memory processes.
文摘OBJECTIVE To investigate the effects of imperatorin on the spatial learning memory impairment and neuroinflammation in model mice of Alzheimer disease(AD)induced by intracerebroventricular injection of Aβ1-42.METHODS Mouse model of AD was established by injection of Aβ1-42 into the lateral ventricles.Im⁃peratorin(2.5 and 5.0 mg·kg-1,daily)was inject⁃ed by intraperitoneally 1 h after intracerebroven⁃tricular injection for 13 d.The effect of imperato⁃rin on the spatial learning and memory impair⁃ment was assessed by eight arm maze tests.The levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in mouse cortex and hip⁃pocampus were detected by ELISA.The protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK were detected by Western blotting.RESULTS As compared with the AD model group,imperatorin treatment significantly attenuated Aβ1-42-induced spatial learning and memory impairment assessed by eight arm maze tests.In addition,imperatorin significantly reduced the levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in the cerebral cortex and hippocampus.Meanwhile,Western blotting results showed that imperatorin treat⁃ment significantly down-regulated the protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK.CONCLUSION Imperatorin has neuroprotective effects in the Aβ1-42 induced AD model mice and its mechanism may be partially associated with the inhibition of inflam⁃matory response in the cortex and hippocampus.
基金supported by the National Natural Science Foundation of China,Nos.81730033,82171193(to XG)the Key Talent Project for Strengthening Health during the 13^(th)Five-Year Plan Period,No.ZDRCA2016069(to XG)+1 种基金the National Key R&D Program of China,No.2018YFC2001901(to XG)Jiangsu Provincial Medical Key Discipline,No.ZDXK202232(to XG)。
文摘Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
基金financially supported by the National Natural Science Foundation of China,No.81303115,81774042 (both to XC)the Pearl River S&T Nova Program of Guangzhou,No.201806010025 (to XC)+3 种基金the Specialty Program of Guangdong Province Hospital of Chinese Medicine of China,No.YN2018ZD07 (to XC)the Natural Science Foundatior of Guangdong Province of China,No.2023A1515012174 (to JL)the Science and Technology Program of Guangzhou of China,No.20210201 0268 (to XC),20210201 0339 (to JS)Guangdong Provincial Key Laboratory of Research on Emergency in TCM,Nos.2018-75,2019-140 (to JS)
文摘Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However,the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood.Here,using mice in which astrocytic endothelin-1 was overexpressed,we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia(1 hour of ischemia;7 days,28 days,or 3 months of reperfusion).We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion.Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6,which were differentially expressed in the brain,were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke.Moreover,the levels of the enriched differentially expressed proteins were closely related to lipid metabolism,as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis.Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine,sphingomyelin,and phosphatidic acid.Overall,this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.
基金supported by grants KSCX2-EW-R-12 and KSCX2-EW-J-23 from the Chinese Academy of Sciences
文摘Recent genome studies indicate that tree shrew is in the order or a closest sister of primates,and thus may be one of the best animals to model human diseases.In this paper,we report on a social defeat model of depression in tree shrew（Tupaia belangeri chinensis）.Two male tree shrews were housed in a pair-cage consisting of two independent cages separated by a wire mesh partition with a door connecting the two cages.After one week adaptation,the connecting door was opened and a brief fighting occurs between the two male tree shrews and this social conflict session consisted of 1 h direct conflict（fighting） and 23 h indirect influence（e.g.smell,visual cues） per day for 21 days.The defeated tree shrew was considered the subordinate.Compared with na？ve animals,subordinate tree shrews at the final week of social conflict session showed alterations in body weight,locomotion,avoidance behavior and urinary cortisol levels.Remarkably,these alterations persisted for over two weeks.We also report on a novel captive conditioning model of learning and memory in tree shrew.An automatic trapping cage was placed in a small closed room with a freely-moving tree shrew.For the first four trials,the tree shrew was not trapped when it entered the cage and ate the bait apple,but it was trapped and kept in the cage for 1 h on the fifth trial.Latency was defined as the time between release of the tree shrew and when it entered the captive cage.Latencies during the five trials indicated adaptation.A test trial 24 h later was used to measure whether the one-trial trapping during the fifth trial could form captive memory.Tree shrews showed much longer trapping latencies in the test trial than the adaptation trials.The N-methyl-d-aspartate（NMDA） receptor antagonist MK-801（0.2 mg/kg,i.p.）,known to prevent the formation of memory,did not affect latencies in the adaptation trails,but did block captive memory as it led to much shorter trapping latencies compared to saline treatment in the test trial.These results demonstrate a chronic social defeat model of depression and a novel one-trial captive conditioning model for learning and memory in tree shrews,which are important for mechanism studies of depression,learning,memory,and preclinical evaluation for new antidepressants.
基金supported by the grants from Nanjing Military Medical Science and Technology Innovation Project (No. 08MA007)
文摘Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of learning and memory after TBI, and to investigate the mechanism of the protective effect of NMDA receptor antagonist MK-801 on learning and memory disorder after TBI. Methods Forty Sprague-Dawley rats （weighing approximately 200 g） were randomized into 5 groups （n = 8 in each group）： control group, model group, low-dose group （MK-801 0.5 mg/kg）, middle-dose group （MK-801 2 mg/kg）, and high-dose group （MK-801 10 mg/kg）. TBI model was established using a weight-drop head injury mode. After 2-month drug treatment, learning and memory ability was evaluated by using Morris water maze test. Then the animals were sacrificed, and brain tissues were taken out for morphological and immunohistochemical assays. Results The ability of learning and memory was significantly impaired in the TBI model animals. Besides, the neuronal caspase-3 expression, neuronal nitric oxide synthase （nNOS）-positive neurons and OX-42-positive microglia were all increased in TBI animals. Meanwhile, the number of neuron synapses was decreased, and vacuoles degeneration could be observed in mitochondria. After MK-801 treatment at 3 different dosages, the ability of learning and memory was markedly improved, as compared to that of the TBI model animals. Moreover, neuronal caspase-3 expression, OX-42-positive microglia and nNOS-positive neurons were all significantly decreased. Meanwhile, the mitochondria degeneration was greatly inhibited. Conclusion MK-801 could significantly inhibit the degeneration and apoptosis of neurons in damaged brain areas. It could also inhibit TBI-induced increase in nNOS-positive neurons and OX-42-positive microglia. Impairment in learning and memory in TBI animals could be repaired by treatment with MK-801.
基金supported by the National Natural Science Foundation of China (No. 30700938,30872656, 30700861, 30800451) the Natural Science Foundation of Liaoning Province, China (No. 20082078)
文摘Objective To investigate whether estrogen modulates learning and memory and long-term potentiation （LTP） in the hippocampus of rats with Alzheimer＇s disease （AD）. Methods The rats were divided into ovariectomy （OVX） and estrogen replacement therapy （ERT） groups. Rats in the ERT group received OVX, followed by ERT, while rats in the OVX group received only OVX. The rat model of AD was established by injection of 1 μL （10 μg/μL） amyloid-beta peptide 1-40（Aβ1-40） into the hippocampus. The learning and memory ability and LTP were determined by Morris water maze and electrophysiological method, respectively. Results The escape latency in Morris water maze significantly decreased in ERT group compared with that in OVX group （P 〈 0.05）. Besides, rats in ERT group exhibited a significant enhancement of the magnitude of LTP at 30 min after high-frequency stimulation （HFS）, compared with that in OVX group （P 〈 0.01）. Conclusion ERT can attenuate the cognitive deficits in the rat model of AD, and estrogen can regulate LTP and synaptic remodeling in AD rats.
基金Supported by:a grant by Sichuan Provincial Science and Technology Bureau,No. 05JY029-103:a grant by Sichuan Provincial Education Bureau.No.2006A152
文摘BACKGROUND： The present study analyzed the effect of 3 days （2 h/d） intrauterine hypoxia on learning and memory in juvenile rats, as well as the therapeutic effects of Angelica sinensis on dentate gyrus neurons, as well as learning and memory. OBJECTIVE： To explore the effects of intrauterine hypoxia on hippocampal dentate gyrus neurons, as well as learning and memory, in juvenile rats; to explore N-methyI-D-aspartate receptor-1 （NMDAR1） expression in the dentate gyrus of neonatal rats following intrauterine hypoxia, as well as prolonged hypoxia; to investigate the regulatory mechanisms of Angelica sinensis. DESIGN, TIME AND SETTING： A randomized and controlled experiment based on developmental neurobiology was performed at the Department of Histology and Embryology in Luzhou Medical College from October 2007 to October 2008. MATERIALS： Angelica sinensis solution （250 g/L） was obtained from Central South Hospital of Wuhan University, China. Neuron-specific enolase and NMDAR1 mRNA in situ hybridization reagents were provided by Wuhan Boster Biological Technology, China. Image-Pro Plus 6.0 analysis system was purchased from Media Cybernetics, USA. METHODS： Healthy pregnant Sprague Dawley rats （n = 30） were randomly divided into control （n = 10）, hypoxia （n = 10）, and Angelica （n = 10） groups. The Angelica and hypoxia pregnant rats were placed in a three-gas incubator （oxygen concentration： 13%） starting with day 14 of pregnancy for 2 hours/day for 5 consecutive days to establish a fetal rat intrauterine hypoxia model. One hour prior to modeling, the pregnant rats from the Angelica and hypoxia groups received Angelica sinensis and normal saline （8 mL/kg） injections, respectively, through the caudal vein. The control group procedures were identical to the hypoxia group, but lacked the hypoxic conditions. MAIN OUTCOME MEASURES： Brain tissues of neonatal rats were used to detect expression of NMDAR1 mRNA, and brain tissues of juvenile rats aged 30 days were used to determine neuron-specific enolase mRNA expression by in situ hybridization. Microscopic images （400x） of the hippocampal dentate gyrus were collected. The integral optical density （IOD） value of positive NMDAR1 mRNA cells in the dentate gyrus of neonatal rats, as well as the quantity and the IOD value of positive neuron-specific enolase mRNA cells in the dentate gyrus of juvenile rats, were analyzed with Image-Pro IPP6.0 software. At 30 days after birth, learning and memory parameters were measured in the juvenile rats using Morris water maze. RESULTS： The quantity and the IOD value of positive neuron-specific enolase mRNA cells in the dentate gyrus of the hypoxia group juvenile rats were significantly less than the control group （P 〈 0.05）, and also less than the Angelica group （P 〈 0.05）. The IOD value of positive NMDAR1 mRNA cells in the dentate gyrus of the hypoxia group neonatal rats was significantly greater than the control group, and also greater than the Angelica group （P 〈 0.05）. In the Morris water maze, the searching time during the probe trial and reversal probe trial was shorter in the hypoxia group juvenile rats compared with the control group, and the Angelica group was prolonged compared with the hypoxia group （P 〈 0.05）. CONCLUSION： Intrauterine hypoxia increased expression of NMDAR1 mRNA in the dentate gyrus of neonatal rats, reduced the number of dentate gyrus neurons, and negatively affected learning and memory in juvenile rats. In contrast, Angelica sinensis injection improved the intrauterine hypoxic condition, increased the number of dentate gyrus neurons, and improved the learning and memory deficits of the juvenile rats.
文摘The present study was designed to determine microtubule-associated protein-2 and synaptophysin expression in the hippocampal CA3 region in a rat model of middle cerebral artery occlusion. The rats were treated with acupuncture at Baihui （GV 20）, Qubin （GB 7）, and Qianding （GV 21） points, in addition to exercise training. Results were compared with rats undergoing exercise training only. The Y-maze method and immunohistochemistry revealed decreased error frequency of passing through Y-maze, as well as significantly increased microtubule-associated protein-2 and synaptophysin expression, in the acupuncture with exercise training group compared with the model and exercise training groups after 5 weeks. Microtubule-associated protein-2 and synaptophysin expressions negatively correlated with error frequency of passing through the Y-maze. These results suggested that acupuncture combined with exercise training improved learning and memory functions in a rat model of cerebral infarction. The mechanisms of action were hypothesized to be associated with dendritic or synaptic plasticity in the ipsilateral hippocampal CA3 region.
基金the Grant from Bureau of Science and Technology of Jining City, No.2004JH006
文摘BACKGROUND： Presently, clinic memory scale is used to evaluate learning memory ability in most studies, and the influence of difference in measurement condition of individuals exists. OBJECTIVE： To study the correlation between regional cerebral blood flow （rCBF） perfusion and learning memory function in special brain regions of patients with cerebral infarction at convalescent period, and to try to find out a method which can quantitatively evaluate learning ability. DESIGN： Case observation, and correlation analysis. SETTINGS： Shandong Institute for Behavioral Medicine; the Affiliated Hospital of Jining Medical College. PARTICIPANTS： Totally 70 patients with cerebral infarction admitted to Department of Neurology, Jining Medical College between January 2004 and December 2005 were involved. The involved patients, 58 male and 12 female, were averaged （52±3） years, and they were all right handed. They all met the diagnosis criteria instituted by the Fourth National Conference on Cerebrovascular Disease, and were confirmed as cerebral infarction by skull CT or MRI. Informed consents of detected items were obtained from all the patients and relatives. METHODS： When the patients were at convalescent period, their learning and memory ability were measured with “ clinic memory scale （set A）”. The 18 patients whose total mark over 100 were regarded as good learning memory function group; The 23 cases whose total mark less than 70 were regarded as poor learning memory function group. RCBF of hippocampus, nucleus amygdalae, temporal cortex and prefrontal lobe of patients between two groups were measured and compared by single photon emission computed tomography （SPECT）. The total scores of the 18 good learning memory patients and 23 poor learning memory patients were taken as dependent variable Y, and their rCBFs of hippocampus, nucleus amygdale, temporal cortex and prefrontal lobe respectively as independent variable X for linear correlation analysis. MAIN OUTCOME MEASURES： Correlation of rCBF in different brain regions and learning memory ability in patients with cerebral infarction. RESULTS： ①The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of good learning memory function group were significantly higher than those of poor learning memory function group （P 〈 0.05）. ②In the good learning memory function group, rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex were significantly positively correlated with memory scale scores （ r = 0.961, 0.926, 0.954, 0.907, P 〈 0.05 ） , and also in the poor learning memory function group （r = 0.979, 0.976, 0.991, 0.953, P 〈 0.05 ） . CONCLUSION： The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of patients with cerebral infarction are significantly positively correlated with memory scale scores. Predicting learning memory ability of patients by quantitative determination of rCBF provides a quantitative and objective method for evaluating learning memory ability.
文摘Microglia are the resident macrophages of the central nervous system.Microglia possess varied morphologies and functions.Under normal physiological conditions,microglia mainly exist in a resting state and constantly monitor their microenvironment and survey neuronal and synaptic activity.Through the C1 q,C3 and CR3"Eat Me"and CD47 and SIRPα"Don't Eat Me"complement pathways,as well as other pathways such as CX3 CR1 signaling,resting microglia regulate synaptic pruning,a process crucial for the promotion of synapse formation and the regulation of neuronal activity and synaptic plasticity.By mediating synaptic pruning,resting microglia play an important role in the regulation of experience-dependent plasticity in the barrel cortex and visual cortex after whisker removal or monocular deprivation,and also in the regulation of learning and memory,including the modulation of memory strength,forgetfulness,and memory quality.As a response to brain injury,infection or neuroinflammation,microglia become activated and increase in number.Activated microglia change to an amoeboid shape,migrate to sites of inflammation and secrete proteins such as cytokines,chemokines and reactive oxygen species.These molecules released by microglia can lead to synaptic plasticity and learning and memory deficits associated with aging,Alzheimer's disease,traumatic brain injury,HIV-associated neurocognitive disorder,and other neurological or mental disorders such as autism,depression and post-traumatic stress disorder.With a focus mainly on recently published literature,here we reviewed the studies investigating the role of resting microglia in synaptic plasticity and learning and memory,as well as how activated microglia modulate disease-related plasticity and learning and memory deficits.By summarizing the function of microglia in these processes,we aim to provide an overview of microglia regulation of synaptic plasticity and learning and memory,and to discuss the possibility of microglia manipulation as a therapeutic to ameliorate cognitive deficits associated with aging,Alzheimer's disease,traumatic brain injury,HIV-associated neurocognitive disorder,and mental disorders.
基金supported by the Annual Key Research Project of Anhui Province(1301043047)
文摘The present study was aimed at determining the effects of Tongqiao Huoxue Decoction （TQHXD） on the Ca2＋-CaMKII-CREB pathway and the memory and learning capacities of rats with vascular dementia （VD）. The rat VD model was established by using an improved bilateral carotid artery ligation method. The Morris water maze experiment was used to evaluate the ethology of the VD rats following treatments with TQHXD at 3.01, 6.02, and 12.04 g.kg-1 per day for 31 days. At the end of experiment, the hippocampus were harvested and analyzed. Western blotting and RT-PCR were used to measure the expression levels of calmodulin-binding protein kinase II（CaMKII）, protein kinase A（PKA）, cAMP-response element binding protein（CREB）, and three N-methyl-D-aspart^c acid receptor subunits （NR1, NR2A, and NR2B）. Our results revealed that TQHXD could alleviate the loss of learning abilities and increase the memory capacity （P 〈 0.05 and P 〈 0.01 vs the model group, respectively）. The treatment with 6.02 and 12.04 g.kg-1 of TQHXD significantly up-regulated the Ca2＋-CaMKII-CREB pathway in the hippocampus. In conclusion, TQHXD showed therapeutic effects on a bilateral carotid artery ligation-induced vascular dementia model, through the up-regulation of calcium signalling oathwavs.
文摘Objective To explore the effects of exercise on dentate gyrus （DG） neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrabippocampal microinjection of kainic acid （KA）. Bromodeoxyuridine （BrdU） was used to label dividing cells. Y maze test was used to evaluate the ability of learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity： lightly running, moderately running, or heavily running. Results Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number （EN） in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. Conclusion Moderate exercise could enhance the DG neurogenesis and ameliorate the ability of learning and memory in hippocampus-lesioned rats.
基金supported by the National Natural Science Foundation of China(61401497)
文摘With key roles in essential brain functions ranging from the long-term potentiation(LTP) to synaptic plasticity,the N-methyl-D-aspartic acid receptor(NMDAR) can be considered as one of the fundamental glutamate receptors in the central nervous system.The role of NMDA R was first identified in synaptic plasticity and has been extensively studied.Some molecules,such as Ca^(2+),postsynaptic density 95(PSD-95),calcium/calmodulin-dependent protein kinase II(Ca MK II),protein kinase A(PKA),mitogen-activated protein kinase(MAPK) and cyclic adenosine monophosphate(c AMP) responsive element binding protein(CREB),are of special importance in learning and memory.This review mainly focused on the new research of key molecules connected with learning and memory,which played important roles in the NMDAR signaling pathway.
基金supported by the Foundation from Department of Education of Hubei Province,No.D20111903
文摘Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clinical symptoms and delay the progression of Alzheimer＇s disease. The present study replicated a rat model of aging induced by injecting quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of eleutheroside B or E （50, 100, 200 mg/kg）, and rats injected with Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose eleutheroside B or E. Hematoxylin-eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced cholinesterase activity, and dose-dependent increases in acetylcholine content and decreases in choline content following eleutheroside B or E treatment, similar to those seen in the Huperzine A group. These findings indicate that eleutheroside B or E improves learning and memory in aged rats. These effects of eleutheroside B or E may be mediated by activation of cholinesterase or enhanced reuse of choline to accelerate the synthesis of acetylcholine in hippocampal neurons.
基金supported by Undergraduate Innovational Experimentation Program of Shanxi Province, China (2009103)
文摘Nitric oxide （NO） is a novel type of neurotransmitter that is closely associated with synaptic plasticity, learning and memory. In the present study, we assessed the effects of Larginine and NnitroL arginine methylester （LNAME, a nitric oxide synthase inhibitor） on learning and memory. Rats were assigned to three groups receiving intracerebroventricular injections of LArg （the NO precursor）, LNAME, or 0.9% NaCI （control）, once daily for seven con secutive days. Twelve hours after the last injection, they underwent an electric shockpaired Y maze test. Twentyfour hours later, the rats＇ memory of the safe illuminated arm was tested. After that, the levels of NO and a7 nicotinic acetylcholine receptor （a7 nAChR） in the prefrontal cortex and hippocampus were assessed using an NO assay kit, and immunohistochemistry and Western blots, respectively. We found that, compared to controls, LArgtreated rats received fewer foot shocks and made fewer errors to reach the learning criterion, and made fewer errors during the memorytesting session. In contrast, LNAMEtreated rats received more foot shocks and made more errors than controls to reach the learning criterion, and made more errors during the memorytesting session. In parallel, NO content in the prefrontal cortex and hippocampus was higher in LArgtreated rats and lower inLNAME rats, compared to controls. Similarly, （]7 nAChR immunoreactivity and protein expression in the prefrontal cortex and hippocampus were higher in LArgtreated rats and lower in LNAME rats, compared to controls. These results suggest that the modulation of NO content in the brain correlates with a7 nAChR distribution and expression in the prefrontal cortex and hippocampus, as well as with learning and memory performance in the Ymaze.
基金the National Natural Science Foundation of China, No: 30560189
文摘BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.
基金financially supported by the National Science and Technology Major Project for New Drug Creation Program by the Ministry of Science and Technology No.2009ZX09502-014
文摘Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extracts may dose-dependently inhibit non-enzymatic saccharification in vitro. This study aimed to examine the effect of Radix Achyranthis Bidentatae on advanced glycation end products and on learning and memory capabilities in ovariectomized rats. Ovariectomized rats were treated with Radix Achyranthis Bidentatae alcohol extracts （containing 1.5 g/kg crude drug） or 0.1% aminoguanidine for 12 weeks and behavioral testing was performed with the Y-electrical maze. This test revealed that Radix Achyranthis Bidentatae and aminoguanidine could improve the learning and memory capabilities of ovariectomized rats. Results of competitive enzyme-linked immunosorbent assay showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine reduced the accumulation of advanced glycation end products in the frontal cortex of ovariectomized rats, while increasing content in the blood and urine. Biochemical tests showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine decreased superoxide dismutase activity in the serum and frontal cortex, and increased serum levels of glutathione peroxidase in ovariectomized rats. In addition there was no apparent effect on malondialdehyde levels. These experimental findings indicate that Radix Achyranthis Bidentatae inhibits production of advanced glycation end products and its accumulation in brain tissue, and improves learning and memory capabilities in ovariectomized rats. These effects may be associated with an anti-oxidative action of the extract.
