Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mecha...Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies.Previous studies primarily focused on neuronal death,potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury.To address these gaps,we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations,altered cell communication networks,and novel molecular mechanisms involved in post-cardiac arrest brain injury.In this study,we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation,and from sham control pigs.Sequencing results revealed changes in the proportions of different cell types,suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils.These results were validated through western blotting,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence staining.We also identified and validated a unique subcluster of activated microglia with high expression of S100A8,which increased over time following cardiac arrest.This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins.Additionally,we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes.Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin,driving pro-inflammatory microglial polarization.Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus,offering potential novel targets for neuroprotection and repair following cardiac arrest.展开更多
BACKGROUND Botulinum neurotoxin(BoNT)is widely recognized as an effective therapeutic agent for managing various neurological disorders,characterized by motor impairments and neuromuscular deficits.BoNT works by modul...BACKGROUND Botulinum neurotoxin(BoNT)is widely recognized as an effective therapeutic agent for managing various neurological disorders,characterized by motor impairments and neuromuscular deficits.BoNT works by modulating the release of acetylcholine at the neuromuscular junction.Recently,BoNT has been shown to enhance spatial memory and attenuate anxiety in experimental aging animals.While neurogenesis in the hippocampus contributes to cognitive properties,BoNT treatment could potentially influence the regulation of adult neurogenesis.As aging-associated microglial activation impairs neurogenesis,the anti-inflammatory properties of BoNT could be associated with the modulation of microglial activity,thereby enhancing cognitive function.AIM To investigate the neurogenic and microglial modulatory properties of BoNT in the hippocampus of aging experimental mice.METHODS Experimental aging mice were administered BoNT and after four weeks,the animals were sacrificed.The brains were subjected to cryosections followed by immunohistochemical analysis to quantify doublecortin(DCX)-positive immature neurons,bromodeoxyuridine(BrdU)-neuronal nuclei(NeuN)double positive newly matured neurons and ionized calcium-binding adapter molecule 1(Iba1)-positive microglia in the hippocampal dentate gyrus.In parallel,an additional set of animals was used to evaluate BoNT-mediated alterations in key inflammatory markers such as cyclooxygenase(COX)-2,and nitric oxide(NO)in hippocampal tissues.RESULTS The results revealed a significant increase in the number of DCX-positive immature neurons and BrdU-NeuN positive differentiated neurons in the hippocampus of the BoNT-treated group compared to the control.This enhancement in neurogenesis was accompanied by a marked reduction in the activated form of microglial cells,coupled with decreased mRNA expression of COX-2 and reduced NO levels in the hippocampus of BoNT-treated animals.CONCLUSION This study validates the proneurogenic and anti-neuroinflammatory properties of BoNT,which may underlie its procognitive effects.Hence,BoNT could be a promising therapeutic agent for treating various neurocognitive disorders.展开更多
Background:Astrocyte endfeet(AEF)serves as a key element of the blood-brain barrier and is important for the survival and maintenance of neuronal function.However,the immunohistochemical and ultrastructural changes of...Background:Astrocyte endfeet(AEF)serves as a key element of the blood-brain barrier and is important for the survival and maintenance of neuronal function.However,the immunohistochemical and ultrastructural changes of AEF in the CA1 and CA3 areas of the hippocampus over time following cerebral ischemia-reperfusion(IR)injury have not been well elucidated.Objectives:We investigated chronological changes in AEF in the gerbil hippocampal CA1 area from 3 h to 10 days following transient forebrain ischemia(TFI),and examined their association with neuronal death and tissue repair following IR injury.Changes in the CA3 area were also examined at 10 days post-TFI for comparative purposes.Methods:Neuronal death was confirmed using histochemistry,immunohistochemistry,and histofluorescence.Changes in AEF were examined by double immunofluorescence with glial fibrillary acidic protein(GFAP)and glucose transporter 1(GLUT1),and by transmission electron microscopy(TEM)for ultrastructural changes.Results:Significant TFI-induced neuronal death occurred in the CA1 area on day 5 following IR injury and persisted until 10 days after TFI,while no neuronal death(or loss)was found in the CA3 area after TFI.Looking at TFI-induced changes in AEF,at 3 and 6 h after TFI,GFAP-immunoreactive(+)AEF in the CA1 area appeared swollen and harbored enlarged,dark mitochondria,and the swelling was reduced by 1-day post-TFI.On 2 and 5 days following TFI,GFAP+AEF were markedly enlarged and fragmented,containing shrunken mitochondria,vacuolations,and sparse organelles.Ten days post-TFI,the ends of GFAP+astrocytic processes extended to microvessels,appeared edematous,and were filled with cellular debris.In the CA3 area,AEF was slightly dilated at 10 days after TFI.These findings indicate that damage to or disruption of AEF in the CA1 area occurs in the early phase after 5-min TFI but is rarely observed in the CA3 area.Conclusion:Taken together,damage to or disruption of AEF following ischemic insults may be strongly linked to neuronal death/loss.展开更多
Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the spec...Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear.Therefore,further investigation is necessary.Methods:We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis,social behavioural tests,hippocampal electrophysiology,immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR.Additionally,we utilized optogenetics and administered ursolic acid(UA)via oral gavage to examine the effects of these agents on social memory in mice.Results:The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1(vCA1)under both physiological conditions and AD-like tau pathology.As tau progressively accumulated,vCA1,especially its excitatory and parvalbumin(PV)neurons,were fully filled with mislocated and phosphorylated tau(p-Tau).This finding was not observed for dorsal hippocampal CA1(dCA1).The overexpression of human tau(hTau)in excitatory and PV neurons mimicked AD-like tau accumulation,significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1.Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory.Notably,1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB(TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory.Conclusion:This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation.Notably,our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.展开更多
Objective To investigate the relations between neuroapoptosis and the onset and development of Alzheimer’s disease （AD）, especially the role of NF-κB in the regulation of neuroapoptosis. Methods Caspase-3 and NF-...Objective To investigate the relations between neuroapoptosis and the onset and development of Alzheimer’s disease （AD）, especially the role of NF-κB in the regulation of neuroapoptosis. Methods Caspase-3 and NF-κB （p50） expressions in the CA3 region of the hippocampus in APPswe Tg2576 transgenic mice were studied from postnatal day 0-180, using Nissl staining, immunohistochemistry and RT-PCR methods. Results Both neuronal apoptosis and NF-κB activity decreased gradually with the increase of age in wild type and Tg2576 mice. However, the number of caspase-3-positive or NF- κB-positive pyramidal cells in Tg2576 mice was greater than that in age-matched wild type mice, with significant differences after postnatal day 14 （P 0.01 or P 0.05）. Linear regression analyses of caspase-3 and NF-κB expression demonstrated a correlation between neuroapoptosis and activity of NF-κB. Conclusion The process of neuroapoptosis is consistent with the onset and development of AD. Furthermore, the observed correlation between neuroapoptosis and NF-κB activity suggests a role of NF-κB in hippocampal neuroapoptosis.展开更多
Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocam...Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocampus in the heroin sensitized rats. Methods Locomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides （AS-ONs） targeting M5 muscarinic receptor was transferred with the lipofectin. Results Microinjection of AS-ONs targeting M5 muscarinic receptor in the ventral tegmental area （VTA） blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus （DG） of the hippocam- pus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M5 muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M5 muscarinic receptor sense oligonucleotide （S-ONs） into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats. Conclusion Blocking M5 muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M5 muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.展开更多
Objective To investigate the expression of amyloid beta precursor-like protein 1 （APLP 1） gene on the transcription level in hippocampus of pilocarpine-induced epileptic rats. Methods Epileptic rats were developed b...Objective To investigate the expression of amyloid beta precursor-like protein 1 （APLP 1） gene on the transcription level in hippocampus of pilocarpine-induced epileptic rats. Methods Epileptic rats were developed by LiCl （3 mmol/kg, i.p.） approximately 20 h prior to pilocarpine （30 mg/kg, i.p.） administration. The 3＇ end partial sequence of rat APLP1 gene was cloned, and the expression levels of APLP1 mRNA in hippocampus of epileptic rats at 6 h, 30 h, 7 d and 15 d were determined by semi-quantitative RT-PCR. Results The 3＇ end partial sequence of rat APLP1 gene shared a 97% homology with that of mice, and 90% with that of human. The APLP1 amino acid sequence of rat was identical with that of mouse, but was different from that of human in 3 residues. Moreover, pilocarpine induced a significant down-regulation ofAPLP1 mRNA expression at 6 h after epilepsy initiation （P 〈 0.05）, and at 30 h, this down-regulation became more dramatic （P 〈 0.01）, which lasted till day 15 （P 〈 0.01）. Conclusion The 3＇ end ofAPLP1 gene is highly conserved, and APLP1 mRNA expression is kept at low level in hippocampus of pilocarpine-induced epileptic rats.展开更多
Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal s...Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal stress alters the phenotype of offspring via immunological mechanisms and that immunological dysfunction, such as elevated interleukin-18 levels, has been reported in cultures of microglia. Prenatal restraint stress(PRS) in rats permits direct experimental investigation of the link between prenatal stress and adverse outcomes. However, the majority of studies have focused on the consequences of PRS delivered in the second half of pregnancy, while the effects of early prenatal stress have rarely been examined. Therefore, pregnant rats were subjected to PRS during early/middle and late gestation(days 8–14 and 15–21, respectively). PRS comprised restraint in a round plastic transparent cylinder under bright light(6500 lx) three times per day for 45 minutes. Differences in interleukin-18 expression in the hippocampus and in behavior were compared between offspring rats and control rats on postnatal day 75. We found that adult male offspring exposed to PRS during their late prenatal periods had higher levels of anxiety-related behavior and depression than control rats, and both male and female offspring exhibited higher levels of depression-related behavior, impaired recognition memory and diminished exploration of novel objects. Moreover, an elevated level of interleukin-18 was observed in the dorsal and ventral hippocampus of male and female early-and late-PRS offspring rats. The results indicate that PRS can cause anxiety and depression-related behaviors in adult offspring and affect the expression of interleukin-18 in the hippocampus. Thus, behavior and the molecular biology of the brain are affected by the timing of PRS exposure and the sex of the offspring. All experiments were approved by the Animal Experimentation Ethics Committee at Kunming Medical University, China(approval No. KMMU2019074) in January 2019.展开更多
A hydroethanolic extract (20% V/V) from Herba Sideritis scardica has been recognized to positively influence cognition. The present investigation aimed at the question if this extract would be able to modify intra-hip...A hydroethanolic extract (20% V/V) from Herba Sideritis scardica has been recognized to positively influence cognition. The present investigation aimed at the question if this extract would be able to modify intra-hippocampal communication after oral administration of 100 mg/kg daily for one week. The glutamatergic synapse between Schaffer Collaterals and pyramidal cells can be tested by electric stimulation using single pulses or theta burst stimulation. The resulting population spike is modulated by compounds acting at the central nervous system or other preparations directly or as ex vivo approach. In this case the effect of the special extract was tested in vitro the next day after repetitive in vitro administration. Conventional recording technique in the in vitro hippocampus slice revealed an increase of the population spike in the presence of single stimuli and theta burst stimuli resulting in increased long-term potentiation. This effect was tried to modulate by several glutamate receptor antagonists, among them compounds targeting at the ionic NMDA receptor (CGS19755), AMPA receptor (NBQX), Kainate receptor (UBP301) and targeting at three metabotropic glutamate receptors (mGluR I (YM298198), mGluRII ((RS)-APICA)) and mGluRIII (MSOP). Only NBQX was able to prevent the action of the Sideritis scardica extract. Since the AMPA receptor has been related to cognition in several reports in the literature, it is concluded from this result that the positive action of Sideritis scardica extract on brain function involves a modulation of AMPA receptor dependent neurotransmission.展开更多
Lung injury is the main manifestation of paraquat poisoning. Few studies have addressed brain damage after paraquat poisoning. Ulinastatin is a protease inhibitor that can effectively stabilize lysosomal membranes, pr...Lung injury is the main manifestation of paraquat poisoning. Few studies have addressed brain damage after paraquat poisoning. Ulinastatin is a protease inhibitor that can effectively stabilize lysosomal membranes, prevent cell damage, and reduce the production of free radicals. This study assumed that ulinastatin would exert these effects on brain tissues that had been poisoned with paraquat. Rat models of paraquat poisoning were intraperitoneally injected with ulinastatin. Simultaneously, rats in the control group were administered normal saline. Hematoxylin-eosin staining showed that most hippocampal cells were contracted and nucleoli had disappeared in the paraquat group. Fewer cells in the hippocampus were concentrated and nucleoli had dis- appeared in the ulinastatin group. Western blot assay showed that expressions of GRP78 and cleaved-caspase-3 were significantly lower in the ulinastatin group than in the paraquat group. Immunohistochemical findings showed that CHOP immunoreactivity was significantly lower in the ulinastatin group than in the paraquat group. Terminal deoxynucleotidyl transferase-medi- ated dUTP nick end labeling staining showed that the number of apoptotic cells was reduced in the paraquat and ulinastatin groups. These data confirmed that endoplasmic reticular stress can be induced by acute paraqnat poisoning. Ulinastatin can effectively inhibit this stress as well as cell apoptosis, thereby exerting a neuroprotective effect.展开更多
Objective To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.Methods Experiments were performed on 184 male Wistar rats（three exposure groups and a sham group）.Mi...Objective To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.Methods Experiments were performed on 184 male Wistar rats（three exposure groups and a sham group）.Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5,5,and 10 mW/cm2.Learning and memory abilities were assessed by Morris water maze.High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus.Hippocampal structures were observed by histopathological analysis.Results Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d,14 d,and 1 m in all three microwave exposure groups.Neurotransmitter concentrations of four amino acids（glutamate,aspartic acid,glycine,and gamma-aminobutyric acid） in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group.There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups.Further,mitochondria became swollen and cristae were disordered.The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles.Conclusion These data suggest that the hippocampus can be injured by long-term microwave exposure,which might result in impairment of cognitive function due to neurotransmitter disruption.展开更多
Modified constraint-induced movement therapy is an effective treatment for neurological and motor impairments in patients with stroke by increasing the use of their affected limb and limiting the contralateral limb.Ho...Modified constraint-induced movement therapy is an effective treatment for neurological and motor impairments in patients with stroke by increasing the use of their affected limb and limiting the contralateral limb.However,the molecular mechanism underlying its efficacy remains unclear.In this study,a middle cerebral artery occlusion(MCAO)rat model was produced by the suture method.Rats received modified constraint-induced movement therapy 1 hour a day for 14 consecutive days,starting from the 7^th day after middle cerebral artery occlusion.Day 1 of treatment lasted for 10 minutes at 2r/min,day 2 for 20 minutes at 2 r/min,and from day 3 onward for 20 minutes at 4 r/min.CatWalk gait analysis,adhesive removal test,and Y-maze test were used to investigate motor function,sensory function as well as cognitive function in rodent animals from the 1st day before MCAO to the 21^st day after MCAO.On the 21^st day after MCAO,the neurotransmitter receptor-related genes from both contralateral and ipsilateral hippocampi were tested by micro-array and then verified by western blot assay.The glutamate related receptor was shown by transmission electron microscopy and the glutamate content was determined by high-performance liquid chromatography.The results of behavior tests showed that modified constraint-induced movement therapy promoted motor and sensory functional recovery in the middle cerebral artery-occluded rats,but had no effect on cognitive function.The modified constraint-induced movement therapy upregulated the expression of glutamate ionotropic receptor AMPA type subunit 3(Gria3)in the hippocampus and downregulated the expression of the beta3-adrenergic receptor gene Adrb3 and arginine vasopressin receptor 1 A,Avprla in the middle cerebral artery-occluded rats.In the ipsilateral hippocampus,only Adra2 a was downregulated,and there was no significant change in Gria3.Transmission electron microscopy revealed a denser distribution the more distribution of postsynaptic glutamate receptor 2/3,which is an a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor,within 240 nm of the postsynaptic density in the contralateral cornu ammonis 3 region.The size and distribution of the synaptic vesicles within 100 nm of the presynaptic active zone were unchanged.Western blot analysis showed that modified constraint-induced movement therapy also increased the expression of glutamate receptor 2/3 and brain-derived neurotrophic factor in the hippocampus of rats with middle cerebral artery occlusion,but had no effect on Synapsin I levels.Besides,we also found modified constraint-induced movement therapy effectively reduced glutamate content in the contralateral hippocampus.This study demonstrated that modified constraint-induced movement therapy is an effective rehabilitation therapy in middle cerebral artery-occluded rats,and suggests that these positive effects occur via the upregulation of the postsynaptic membrane a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor expression.This study was approved by the Institutional Animal Care and Use Committee of Fudan University,China(approval No.201802173 S)on March 3,2018.展开更多
Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor （BDNF）. In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of po...Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor （BDNF）. In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.展开更多
Anxiety disorders are currently a major psychiatric and social problem,the mechanisms of which have been only partially elucidated.The hippocampus serves as a major target of stress mediators and is closely related to...Anxiety disorders are currently a major psychiatric and social problem,the mechanisms of which have been only partially elucidated.The hippocampus serves as a major target of stress mediators and is closely related to anxiety modulation.Yet so far,its complex anatomy has been a challenge for research on the mechanisms of anxiety regulation.Recent advances in imaging,virus tracking,and optogenetics/chemogenetics have permitted elucidation of the activity,connectivity,and function of specific cell types within the hippocampus and its connected brain regions,providing mechanistic insights into the elaborate organization of the hippocampal circuitry underlying anxiety.Studies of hippocampal neurotransmitter systems,including glutamatergic,GABAergic,cholinergic,dopaminergic,and serotonergic systems,have contributed to the interpretation of the underlying neural mechanisms of anxiety.Neuropeptides and neuroinflammatory factors are also involved in anxiety modulation.This review comprehensively summarizes the hippocampal mechanisms associated with anxiety modulation,based on molecular,cellular,and circuit properties,to provide tailored targets for future anxiety treatment.展开更多
Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyI-D-aspartate receptor （NMDAR） signaling pathway to establish whether this plays a role in synaptic plasticity imp...Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyI-D-aspartate receptor （NMDAR） signaling pathway to establish whether this plays a role in synaptic plasticity impairment. Methods 48 male Wistar rats were exposed to 30 mW/cm^2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H＆E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm^2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. Results Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits （NR1, NR2A, and NR2B） and related signaling molecules （CaZ＋/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein） were examined. Conclusion 30 mW/cm^2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.展开更多
OBJECTIVE: To investigate the effects of combined acupuncture and eugenol on learning-memory ability and the antioxidation system of the hippocampus in Alzheimer disease (AD) rats. METHODS: Sixty Sprague Dawley rats, ...OBJECTIVE: To investigate the effects of combined acupuncture and eugenol on learning-memory ability and the antioxidation system of the hippocampus in Alzheimer disease (AD) rats. METHODS: Sixty Sprague Dawley rats, weighing (300±10) g, were randomly divided with 10 rats per group into a normal control group, AD model group, AD with cut olfactory nerve group, Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group. The AD model was established by injection of amyloid β1-40 (Aβ 1-40). Morris maze tests were conducted for evaluating the learning-memory ability. Content of malo- ndialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the hippocampus were detected. RESULTS: The average escape latency and the mean swimming distance in the normal control group, the Xiu three-needle group, the eugenol group, and the combined acupuncture and euge-nol group were significantly shorter than those in the AD model group (all P<0.01). The combined acupuncture and eugenol group had shorter escape latency and mean swimming distance than those in the Xiu three-needle group and the eugenol group. There were no significant differences between the Xiu three-needle group and the eugenol group and between the AD group and the AD with cut olfactory nerve group (P>0.05). Compared with the normal control group, the MDA content in the hippocampus significantly increased (P<0.05) and GSH-Px and SOD activities significantly decreased in the AD model group (P<0.01). Compared with the AD model group, significantly decreased (P< 0.01) and SOD and GSH-Px activities significantly increased in the Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group (P<0.05). Compared with the Xiu three-needle group and eugenol group, the MDA content significantly decreased (P<0.05) and SOD and GSH-Px activities increased (P<0.05) in the combined acupuncture and eugenol group. There were no significant differences among the three indices between the Xiu three-needle group and the eugenol group and between the AD model group and the AD with cut olfactory nerve group (P>0.05). CONCLUSION: Both Xiu three-needle and eugenol can increase learning-memory ability, decrease MDA content, and increase SOD and GSH-Px activities in the hippocampus in AD rats. The combination of acupuncture with eugenol has stronger effects, and the effects depend on the olfactory pathway.展开更多
Electroacupuncture(EA)has been shown to reduce blood lipid level and improve cerebral ischemia in rats with hyperlipemia complicated by cerebral ischemia.However,there are few studies on the results and mechanism of t...Electroacupuncture(EA)has been shown to reduce blood lipid level and improve cerebral ischemia in rats with hyperlipemia complicated by cerebral ischemia.However,there are few studies on the results and mechanism of the effect of EA in reducing blood lipid level or promoting neural repair after stroke in hyperlipidemic subjects.In this study,EA was applied to a rat model of hyperlipidemia and middle cerebral artery thrombosis and the condition of neurons and astrocytes after hippocampal injury was assessed.Except for the normal group,rats in other groups were fed a high-fat diet throughout the whole experiment.Hyperlipidemia models were established in rats fed a high-fat diet for 6 weeks.Middle cerebral artery thrombus models were induced by pasting 50%FeCl3 filter paper on the left middle cerebral artery for 20 minutes on day 50 as the model group.EA1 group rats received EA at bilateral ST40(Fenglong)for 7 days before the thrombosis.Rats in the EA1 and EA2 groups received EA at GV20(Baihui)and bilateral ST40 for 14 days after model establishment.Neuronal health was assessed by hematoxylin-eosin staining in the brain.Hyperlipidemia was assessed by biochemical methods that measured total cholesterol,triglyceride,low-density lipoprotein and high-density lipoprotein in blood sera.Behavioral analysis was used to confirm the establishment of the model.Immunohistochemical methods were used to detect the expression of glial fibrillary acidic protein and nerve growth factor in the hippocampal CA1 region.The results demonstrated that,compared with the model group,blood lipid levels significantly decreased,glial fibrillary acidic protein immunoreactivity was significantly weakened and nerve growth factor immunoreactivity was significantly enhanced in the EA1 and EA2 groups.The repair effect was superior in the EA1 group than in the EA2 group.These findings confirm that EA can reduce blood lipid,inhibit glial fibrillary acidic protein expression and promote nerve growth factor expression in the hippocampal CA1 region after hyperlipidemia and middle cerebral artery thrombosis.All experimental procedures and protocols were approved by the Animal Use and Management Committee of Beijing University of Chinese Medicine,China(approval No.BUCM-3-2018022802-1002)on April 12,2018.展开更多
Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury.To further identify the involved mechanisms,we assumed that electroacupuncture used to treat cerebr...Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury.To further identify the involved mechanisms,we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase（MAPK） signaling pathway.We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa＇s method.At 30 minutes before model establishment,p38 MAPK blocker SB20358 was injected into the left lateral ventricles.At 1.5 hours after model establishment,electroacupuncture was administered at acupoints of Chize（LU5）,Hegu（LI4）,Zusanli（ST36）,and Sanyinjiao（SP6） for 20 minutes in the affected side.Results showed that the combination of EA and SB20358 injection significantly decreased neurologic impairment scores,but no significant differences were determined among different interventional groups.Hematoxylin-eosin staining also showed reduced brain tissue injuries.Compared with the SB20358 group,the cells were regularly arranged,the structures were complete,and the number of viable neurons was higher in the SB20358 ＋ electroacupuncture group.Terminal deoxynucleotidyl transferase（Td T）-mediated d UTP nick-end labeling assay showed a decreased apoptotic index in each group,with a significant decrease in the SB20358 ＋ electroacupuncture group.Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 ＋ electroacupuncture group compared with the ischemia/reperfusion group.There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group.These findings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway.A time period of 3 days could promote the repair of ischemic cerebral nerves.展开更多
OBJECTIVE:This work aims to observe the effects of electroacupuncture on brain-derived neuro-trophic factor(BDNF)mRNA expression in mouse hippocampus following cerebral ischemia-reperfu-sion injury.METHODS:The models ...OBJECTIVE:This work aims to observe the effects of electroacupuncture on brain-derived neuro-trophic factor(BDNF)mRNA expression in mouse hippocampus following cerebral ischemia-reperfu-sion injury.METHODS:The models of mouse cerebral isch-emia-reperfusion injury were established.A total of 96 healthy mice were randomly assigned into 4 groups,namely,the sham surgery,model,mod-el+electroacupuncture,and mode+hydergine groups.Mice in the model+electroacupuncturegroup were treated through electroacupuncture at the Shenshu(BL 23),Geshu(BL 17),and Baihui(GV 20)acupoints.Mice in the model+hydergine group were intragastrically administered with hy-dergine(0.77 mg/kg-1.day-l).The levels of BDNF mRNA expressions in the hippocampus were ana-lyzed through a semi-quantitative reverse transcrip-tion-polymerase chain reaction assay on days 1 and 7 after the surgeries.RESULTS:BDNF mRNA expressions in the mouse hippocampus of the model group on days 1 and 7 after the surgery were higher than those of the sham surgery group(both P〈0.01).On days 1 and 7 of the electroacupuncture treatment,BDNF mRNA expression in the mouse hippocampus of the mod-el+electroacupuncture group was significantly ele-vated compared with the model group(both P〈0.01)or the model+hydergine group(both P〈0.01).On days 1 and 7 of the hydergine treatment,BDNF mRNA expression in the mouse hippocam-pus of the model+hydergine group tended to in-crease compared with the model group;however,statistical significance was not achieved(both P〉0.05).CONCLUSION:Electroacupuncture treatment en-hances endogenous BDNF expression,which may improve the survival environment for intracerebral neurons and inhibit the apoptosis of hippocampal cells.展开更多
Aging is a key risk factor for cognitive decline and age-related neurodegenerative disorders. Also, an age-related decrease in sex steroid hormones may have a negative impact on the formation of neurofibrillary tangl...Aging is a key risk factor for cognitive decline and age-related neurodegenerative disorders. Also, an age-related decrease in sex steroid hormones may have a negative impact on the formation of neurofibrillary tangles （NFTs）; these hormones can regulate Tau phosphorylation and the principal kinase GSK3β involved in this process. Hormone replacement therapy decreases NFTs, but it increases the risk of some types of cancer. However, other synthetic hormones such as tibolone （TIB） have been used for hormone replacement therapy. The aim of this work was to evaluate the long-term effects of TIB （0.01 mg/kg and 1mg/kg, intragastrically for 12 weeks） on the content of total and hyperphosphorylated Tau （PHF-1） proteins and the regulation of GSK3β/Akt/PI3K pathway and CDK5/p35/p25 complexes in the hippocampus of aged male mice. We observed that the content of PHF-1 decreased with TIB administration. In contrast, no changes were observed in the active form of GSK3β or PI3K. TIB decreased the expression of the total and phosphorylated form of Akt while increased that of p110 and p85. The content of CDK5 was differentially modified with TIB： it was increased at low doses and decreased at high doses. When we analyzed the content of CDK5 activators, an increase was found on p35; however, the content of p25 decreased with administration of low dose of TIB. Our results suggest a possible mechanism of action of TIB in the hippocampus of aged male mice. Through the regulation of Tau and GSK3β/Akt/PI3K pathway, and CDK5/p35/p25 complexes, TIB may modulate neuronal plasticity and regulate learning and memory processes.展开更多
基金supported by the National Science Foundation of China,Nos.82325031(to FX),82030059(to YC),82102290(to YG),U23A20485(to YC)Noncommunicable Chronic Diseases-National Science and Technology Major Project,No.2023ZD0505504(to FX),2023ZD0505500(to YC)the Key R&D Program of Shandong Province,No.2022ZLGX03(to YC).
文摘Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies.Previous studies primarily focused on neuronal death,potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury.To address these gaps,we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations,altered cell communication networks,and novel molecular mechanisms involved in post-cardiac arrest brain injury.In this study,we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation,and from sham control pigs.Sequencing results revealed changes in the proportions of different cell types,suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils.These results were validated through western blotting,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence staining.We also identified and validated a unique subcluster of activated microglia with high expression of S100A8,which increased over time following cardiac arrest.This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins.Additionally,we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes.Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin,driving pro-inflammatory microglial polarization.Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus,offering potential novel targets for neuroprotection and repair following cardiac arrest.
基金Supported by the Science and Engineering Research Board(SERB),No.SERB-EEQ/2016/000639RUSA 2.0,Biological Sciences,Bharathidasan University,No.TN RUSA:311/RUSA(2.0)/2018 dt.December 2,2020+1 种基金the University Grants Commission,Faculty Recharge Programme(UGC-FRP),New Delhi,IndiaCouncil of Scientific and Industrial Research-Senior Research Fellowship(CSIRSRF)-Direct,No.09/0475(23353)/2025-EMR-I.
文摘BACKGROUND Botulinum neurotoxin(BoNT)is widely recognized as an effective therapeutic agent for managing various neurological disorders,characterized by motor impairments and neuromuscular deficits.BoNT works by modulating the release of acetylcholine at the neuromuscular junction.Recently,BoNT has been shown to enhance spatial memory and attenuate anxiety in experimental aging animals.While neurogenesis in the hippocampus contributes to cognitive properties,BoNT treatment could potentially influence the regulation of adult neurogenesis.As aging-associated microglial activation impairs neurogenesis,the anti-inflammatory properties of BoNT could be associated with the modulation of microglial activity,thereby enhancing cognitive function.AIM To investigate the neurogenic and microglial modulatory properties of BoNT in the hippocampus of aging experimental mice.METHODS Experimental aging mice were administered BoNT and after four weeks,the animals were sacrificed.The brains were subjected to cryosections followed by immunohistochemical analysis to quantify doublecortin(DCX)-positive immature neurons,bromodeoxyuridine(BrdU)-neuronal nuclei(NeuN)double positive newly matured neurons and ionized calcium-binding adapter molecule 1(Iba1)-positive microglia in the hippocampal dentate gyrus.In parallel,an additional set of animals was used to evaluate BoNT-mediated alterations in key inflammatory markers such as cyclooxygenase(COX)-2,and nitric oxide(NO)in hippocampal tissues.RESULTS The results revealed a significant increase in the number of DCX-positive immature neurons and BrdU-NeuN positive differentiated neurons in the hippocampus of the BoNT-treated group compared to the control.This enhancement in neurogenesis was accompanied by a marked reduction in the activated form of microglial cells,coupled with decreased mRNA expression of COX-2 and reduced NO levels in the hippocampus of BoNT-treated animals.CONCLUSION This study validates the proneurogenic and anti-neuroinflammatory properties of BoNT,which may underlie its procognitive effects.Hence,BoNT could be a promising therapeutic agent for treating various neurocognitive disorders.
基金supported by 2024 Research Grant from Kangwon National University(M.C.S)and the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2021R1A2C1094224)(J.H.A).
文摘Background:Astrocyte endfeet(AEF)serves as a key element of the blood-brain barrier and is important for the survival and maintenance of neuronal function.However,the immunohistochemical and ultrastructural changes of AEF in the CA1 and CA3 areas of the hippocampus over time following cerebral ischemia-reperfusion(IR)injury have not been well elucidated.Objectives:We investigated chronological changes in AEF in the gerbil hippocampal CA1 area from 3 h to 10 days following transient forebrain ischemia(TFI),and examined their association with neuronal death and tissue repair following IR injury.Changes in the CA3 area were also examined at 10 days post-TFI for comparative purposes.Methods:Neuronal death was confirmed using histochemistry,immunohistochemistry,and histofluorescence.Changes in AEF were examined by double immunofluorescence with glial fibrillary acidic protein(GFAP)and glucose transporter 1(GLUT1),and by transmission electron microscopy(TEM)for ultrastructural changes.Results:Significant TFI-induced neuronal death occurred in the CA1 area on day 5 following IR injury and persisted until 10 days after TFI,while no neuronal death(or loss)was found in the CA3 area after TFI.Looking at TFI-induced changes in AEF,at 3 and 6 h after TFI,GFAP-immunoreactive(+)AEF in the CA1 area appeared swollen and harbored enlarged,dark mitochondria,and the swelling was reduced by 1-day post-TFI.On 2 and 5 days following TFI,GFAP+AEF were markedly enlarged and fragmented,containing shrunken mitochondria,vacuolations,and sparse organelles.Ten days post-TFI,the ends of GFAP+astrocytic processes extended to microvessels,appeared edematous,and were filled with cellular debris.In the CA3 area,AEF was slightly dilated at 10 days after TFI.These findings indicate that damage to or disruption of AEF in the CA1 area occurs in the early phase after 5-min TFI but is rarely observed in the CA3 area.Conclusion:Taken together,damage to or disruption of AEF following ischemic insults may be strongly linked to neuronal death/loss.
基金supported in part by the National Natural Science Foundation of China(91949205,82071219,82001134,31730035,81721005,and 82201584)the Hubei Provincial Key S&T Program(2018ACA142)the Guangdong Provincial Key S&T Program(2018B030336001).
文摘Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear.Therefore,further investigation is necessary.Methods:We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis,social behavioural tests,hippocampal electrophysiology,immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR.Additionally,we utilized optogenetics and administered ursolic acid(UA)via oral gavage to examine the effects of these agents on social memory in mice.Results:The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1(vCA1)under both physiological conditions and AD-like tau pathology.As tau progressively accumulated,vCA1,especially its excitatory and parvalbumin(PV)neurons,were fully filled with mislocated and phosphorylated tau(p-Tau).This finding was not observed for dorsal hippocampal CA1(dCA1).The overexpression of human tau(hTau)in excitatory and PV neurons mimicked AD-like tau accumulation,significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1.Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory.Notably,1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB(TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory.Conclusion:This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation.Notably,our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.
基金supported by theNational Natural Science Foundation of China (No. 30670688,30771140)the Natural Science Foundation of Education De-partment of Henan Province (No. 2007180008)+1 种基金the Natural Science Key Program of Henan University (No. 2008YBGG048)the International Cooperation Program of Science andTechnique Department of Henan Province, China (No.094300510044)
文摘Objective To investigate the relations between neuroapoptosis and the onset and development of Alzheimer’s disease （AD）, especially the role of NF-κB in the regulation of neuroapoptosis. Methods Caspase-3 and NF-κB （p50） expressions in the CA3 region of the hippocampus in APPswe Tg2576 transgenic mice were studied from postnatal day 0-180, using Nissl staining, immunohistochemistry and RT-PCR methods. Results Both neuronal apoptosis and NF-κB activity decreased gradually with the increase of age in wild type and Tg2576 mice. However, the number of caspase-3-positive or NF- κB-positive pyramidal cells in Tg2576 mice was greater than that in age-matched wild type mice, with significant differences after postnatal day 14 （P 0.01 or P 0.05）. Linear regression analyses of caspase-3 and NF-κB expression demonstrated a correlation between neuroapoptosis and activity of NF-κB. Conclusion The process of neuroapoptosis is consistent with the onset and development of AD. Furthermore, the observed correlation between neuroapoptosis and NF-κB activity suggests a role of NF-κB in hippocampal neuroapoptosis.
基金This work was supported by the National Nature Science Foundation of China （No.30470554）the National Basic Research Development Program of China（No.2003CB515404）.
文摘Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocampus in the heroin sensitized rats. Methods Locomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides （AS-ONs） targeting M5 muscarinic receptor was transferred with the lipofectin. Results Microinjection of AS-ONs targeting M5 muscarinic receptor in the ventral tegmental area （VTA） blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus （DG） of the hippocam- pus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M5 muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M5 muscarinic receptor sense oligonucleotide （S-ONs） into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats. Conclusion Blocking M5 muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M5 muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.
基金supported by the National Basic Research Development Program of China (No.2006CB504501)National Key Laboratory of Modern Communication Foundation of China (9140C1101050701)the National Natural Sciences Foundation of China (No.30525030)
文摘Objective To investigate the expression of amyloid beta precursor-like protein 1 （APLP 1） gene on the transcription level in hippocampus of pilocarpine-induced epileptic rats. Methods Epileptic rats were developed by LiCl （3 mmol/kg, i.p.） approximately 20 h prior to pilocarpine （30 mg/kg, i.p.） administration. The 3＇ end partial sequence of rat APLP1 gene was cloned, and the expression levels of APLP1 mRNA in hippocampus of epileptic rats at 6 h, 30 h, 7 d and 15 d were determined by semi-quantitative RT-PCR. Results The 3＇ end partial sequence of rat APLP1 gene shared a 97% homology with that of mice, and 90% with that of human. The APLP1 amino acid sequence of rat was identical with that of mouse, but was different from that of human in 3 residues. Moreover, pilocarpine induced a significant down-regulation ofAPLP1 mRNA expression at 6 h after epilepsy initiation （P 〈 0.05）, and at 30 h, this down-regulation became more dramatic （P 〈 0.01）, which lasted till day 15 （P 〈 0.01）. Conclusion The 3＇ end ofAPLP1 gene is highly conserved, and APLP1 mRNA expression is kept at low level in hippocampus of pilocarpine-induced epileptic rats.
基金supported by the National Natural Science Foundation of China,No.81260296(to LJA)and 81300987(to QLi)
文摘Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal stress alters the phenotype of offspring via immunological mechanisms and that immunological dysfunction, such as elevated interleukin-18 levels, has been reported in cultures of microglia. Prenatal restraint stress(PRS) in rats permits direct experimental investigation of the link between prenatal stress and adverse outcomes. However, the majority of studies have focused on the consequences of PRS delivered in the second half of pregnancy, while the effects of early prenatal stress have rarely been examined. Therefore, pregnant rats were subjected to PRS during early/middle and late gestation(days 8–14 and 15–21, respectively). PRS comprised restraint in a round plastic transparent cylinder under bright light(6500 lx) three times per day for 45 minutes. Differences in interleukin-18 expression in the hippocampus and in behavior were compared between offspring rats and control rats on postnatal day 75. We found that adult male offspring exposed to PRS during their late prenatal periods had higher levels of anxiety-related behavior and depression than control rats, and both male and female offspring exhibited higher levels of depression-related behavior, impaired recognition memory and diminished exploration of novel objects. Moreover, an elevated level of interleukin-18 was observed in the dorsal and ventral hippocampus of male and female early-and late-PRS offspring rats. The results indicate that PRS can cause anxiety and depression-related behaviors in adult offspring and affect the expression of interleukin-18 in the hippocampus. Thus, behavior and the molecular biology of the brain are affected by the timing of PRS exposure and the sex of the offspring. All experiments were approved by the Animal Experimentation Ethics Committee at Kunming Medical University, China(approval No. KMMU2019074) in January 2019.
文摘A hydroethanolic extract (20% V/V) from Herba Sideritis scardica has been recognized to positively influence cognition. The present investigation aimed at the question if this extract would be able to modify intra-hippocampal communication after oral administration of 100 mg/kg daily for one week. The glutamatergic synapse between Schaffer Collaterals and pyramidal cells can be tested by electric stimulation using single pulses or theta burst stimulation. The resulting population spike is modulated by compounds acting at the central nervous system or other preparations directly or as ex vivo approach. In this case the effect of the special extract was tested in vitro the next day after repetitive in vitro administration. Conventional recording technique in the in vitro hippocampus slice revealed an increase of the population spike in the presence of single stimuli and theta burst stimuli resulting in increased long-term potentiation. This effect was tried to modulate by several glutamate receptor antagonists, among them compounds targeting at the ionic NMDA receptor (CGS19755), AMPA receptor (NBQX), Kainate receptor (UBP301) and targeting at three metabotropic glutamate receptors (mGluR I (YM298198), mGluRII ((RS)-APICA)) and mGluRIII (MSOP). Only NBQX was able to prevent the action of the Sideritis scardica extract. Since the AMPA receptor has been related to cognition in several reports in the literature, it is concluded from this result that the positive action of Sideritis scardica extract on brain function involves a modulation of AMPA receptor dependent neurotransmission.
基金supported by a grant from the National Key Specialty Construction Project in China in 2012,No.[2012]650
文摘Lung injury is the main manifestation of paraquat poisoning. Few studies have addressed brain damage after paraquat poisoning. Ulinastatin is a protease inhibitor that can effectively stabilize lysosomal membranes, prevent cell damage, and reduce the production of free radicals. This study assumed that ulinastatin would exert these effects on brain tissues that had been poisoned with paraquat. Rat models of paraquat poisoning were intraperitoneally injected with ulinastatin. Simultaneously, rats in the control group were administered normal saline. Hematoxylin-eosin staining showed that most hippocampal cells were contracted and nucleoli had disappeared in the paraquat group. Fewer cells in the hippocampus were concentrated and nucleoli had dis- appeared in the ulinastatin group. Western blot assay showed that expressions of GRP78 and cleaved-caspase-3 were significantly lower in the ulinastatin group than in the paraquat group. Immunohistochemical findings showed that CHOP immunoreactivity was significantly lower in the ulinastatin group than in the paraquat group. Terminal deoxynucleotidyl transferase-medi- ated dUTP nick end labeling staining showed that the number of apoptotic cells was reduced in the paraquat and ulinastatin groups. These data confirmed that endoplasmic reticular stress can be induced by acute paraqnat poisoning. Ulinastatin can effectively inhibit this stress as well as cell apoptosis, thereby exerting a neuroprotective effect.
基金supported by the National Natural Science Foundation of China (No. 30901169)
文摘Objective To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.Methods Experiments were performed on 184 male Wistar rats（three exposure groups and a sham group）.Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5,5,and 10 mW/cm2.Learning and memory abilities were assessed by Morris water maze.High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus.Hippocampal structures were observed by histopathological analysis.Results Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d,14 d,and 1 m in all three microwave exposure groups.Neurotransmitter concentrations of four amino acids（glutamate,aspartic acid,glycine,and gamma-aminobutyric acid） in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group.There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups.Further,mitochondria became swollen and cristae were disordered.The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles.Conclusion These data suggest that the hippocampus can be injured by long-term microwave exposure,which might result in impairment of cognitive function due to neurotransmitter disruption.
基金supported by the National Natural Science Foundation of China,No.81871841(to YLB) and No.81772453(to DSX)
文摘Modified constraint-induced movement therapy is an effective treatment for neurological and motor impairments in patients with stroke by increasing the use of their affected limb and limiting the contralateral limb.However,the molecular mechanism underlying its efficacy remains unclear.In this study,a middle cerebral artery occlusion(MCAO)rat model was produced by the suture method.Rats received modified constraint-induced movement therapy 1 hour a day for 14 consecutive days,starting from the 7^th day after middle cerebral artery occlusion.Day 1 of treatment lasted for 10 minutes at 2r/min,day 2 for 20 minutes at 2 r/min,and from day 3 onward for 20 minutes at 4 r/min.CatWalk gait analysis,adhesive removal test,and Y-maze test were used to investigate motor function,sensory function as well as cognitive function in rodent animals from the 1st day before MCAO to the 21^st day after MCAO.On the 21^st day after MCAO,the neurotransmitter receptor-related genes from both contralateral and ipsilateral hippocampi were tested by micro-array and then verified by western blot assay.The glutamate related receptor was shown by transmission electron microscopy and the glutamate content was determined by high-performance liquid chromatography.The results of behavior tests showed that modified constraint-induced movement therapy promoted motor and sensory functional recovery in the middle cerebral artery-occluded rats,but had no effect on cognitive function.The modified constraint-induced movement therapy upregulated the expression of glutamate ionotropic receptor AMPA type subunit 3(Gria3)in the hippocampus and downregulated the expression of the beta3-adrenergic receptor gene Adrb3 and arginine vasopressin receptor 1 A,Avprla in the middle cerebral artery-occluded rats.In the ipsilateral hippocampus,only Adra2 a was downregulated,and there was no significant change in Gria3.Transmission electron microscopy revealed a denser distribution the more distribution of postsynaptic glutamate receptor 2/3,which is an a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor,within 240 nm of the postsynaptic density in the contralateral cornu ammonis 3 region.The size and distribution of the synaptic vesicles within 100 nm of the presynaptic active zone were unchanged.Western blot analysis showed that modified constraint-induced movement therapy also increased the expression of glutamate receptor 2/3 and brain-derived neurotrophic factor in the hippocampus of rats with middle cerebral artery occlusion,but had no effect on Synapsin I levels.Besides,we also found modified constraint-induced movement therapy effectively reduced glutamate content in the contralateral hippocampus.This study demonstrated that modified constraint-induced movement therapy is an effective rehabilitation therapy in middle cerebral artery-occluded rats,and suggests that these positive effects occur via the upregulation of the postsynaptic membrane a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor expression.This study was approved by the Institutional Animal Care and Use Committee of Fudan University,China(approval No.201802173 S)on March 3,2018.
基金supported by a grant from the Experimental Animal Science and Technology Project of Zhejiang Province in China,No.2012C37083
文摘Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor （BDNF）. In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.
基金supported by the National Natural Science Foundation of China(31970951)the Six Talent Peaks Project of Jiangsu Province(YY-005)+1 种基金the Shanghai Rising-Star Program(21QA1407900)“Zhong Ying Young Scholar”project of Cyrus Tang Foundation.
文摘Anxiety disorders are currently a major psychiatric and social problem,the mechanisms of which have been only partially elucidated.The hippocampus serves as a major target of stress mediators and is closely related to anxiety modulation.Yet so far,its complex anatomy has been a challenge for research on the mechanisms of anxiety regulation.Recent advances in imaging,virus tracking,and optogenetics/chemogenetics have permitted elucidation of the activity,connectivity,and function of specific cell types within the hippocampus and its connected brain regions,providing mechanistic insights into the elaborate organization of the hippocampal circuitry underlying anxiety.Studies of hippocampal neurotransmitter systems,including glutamatergic,GABAergic,cholinergic,dopaminergic,and serotonergic systems,have contributed to the interpretation of the underlying neural mechanisms of anxiety.Neuropeptides and neuroinflammatory factors are also involved in anxiety modulation.This review comprehensively summarizes the hippocampal mechanisms associated with anxiety modulation,based on molecular,cellular,and circuit properties,to provide tailored targets for future anxiety treatment.
基金supported by the National Natural Science Foundation of China(No.81172620)
文摘Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyI-D-aspartate receptor （NMDAR） signaling pathway to establish whether this plays a role in synaptic plasticity impairment. Methods 48 male Wistar rats were exposed to 30 mW/cm^2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H＆E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm^2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. Results Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits （NR1, NR2A, and NR2B） and related signaling molecules （CaZ＋/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein） were examined. Conclusion 30 mW/cm^2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.
基金Supported by a Grant from the National Natural Sciences Foundation of China(No.30973792)
文摘OBJECTIVE: To investigate the effects of combined acupuncture and eugenol on learning-memory ability and the antioxidation system of the hippocampus in Alzheimer disease (AD) rats. METHODS: Sixty Sprague Dawley rats, weighing (300±10) g, were randomly divided with 10 rats per group into a normal control group, AD model group, AD with cut olfactory nerve group, Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group. The AD model was established by injection of amyloid β1-40 (Aβ 1-40). Morris maze tests were conducted for evaluating the learning-memory ability. Content of malo- ndialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the hippocampus were detected. RESULTS: The average escape latency and the mean swimming distance in the normal control group, the Xiu three-needle group, the eugenol group, and the combined acupuncture and euge-nol group were significantly shorter than those in the AD model group (all P<0.01). The combined acupuncture and eugenol group had shorter escape latency and mean swimming distance than those in the Xiu three-needle group and the eugenol group. There were no significant differences between the Xiu three-needle group and the eugenol group and between the AD group and the AD with cut olfactory nerve group (P>0.05). Compared with the normal control group, the MDA content in the hippocampus significantly increased (P<0.05) and GSH-Px and SOD activities significantly decreased in the AD model group (P<0.01). Compared with the AD model group, significantly decreased (P< 0.01) and SOD and GSH-Px activities significantly increased in the Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group (P<0.05). Compared with the Xiu three-needle group and eugenol group, the MDA content significantly decreased (P<0.05) and SOD and GSH-Px activities increased (P<0.05) in the combined acupuncture and eugenol group. There were no significant differences among the three indices between the Xiu three-needle group and the eugenol group and between the AD model group and the AD with cut olfactory nerve group (P>0.05). CONCLUSION: Both Xiu three-needle and eugenol can increase learning-memory ability, decrease MDA content, and increase SOD and GSH-Px activities in the hippocampus in AD rats. The combination of acupuncture with eugenol has stronger effects, and the effects depend on the olfactory pathway.
基金This study was funded by the National Natural Science Foundation of China,No.81470200(to XJR).
文摘Electroacupuncture(EA)has been shown to reduce blood lipid level and improve cerebral ischemia in rats with hyperlipemia complicated by cerebral ischemia.However,there are few studies on the results and mechanism of the effect of EA in reducing blood lipid level or promoting neural repair after stroke in hyperlipidemic subjects.In this study,EA was applied to a rat model of hyperlipidemia and middle cerebral artery thrombosis and the condition of neurons and astrocytes after hippocampal injury was assessed.Except for the normal group,rats in other groups were fed a high-fat diet throughout the whole experiment.Hyperlipidemia models were established in rats fed a high-fat diet for 6 weeks.Middle cerebral artery thrombus models were induced by pasting 50%FeCl3 filter paper on the left middle cerebral artery for 20 minutes on day 50 as the model group.EA1 group rats received EA at bilateral ST40(Fenglong)for 7 days before the thrombosis.Rats in the EA1 and EA2 groups received EA at GV20(Baihui)and bilateral ST40 for 14 days after model establishment.Neuronal health was assessed by hematoxylin-eosin staining in the brain.Hyperlipidemia was assessed by biochemical methods that measured total cholesterol,triglyceride,low-density lipoprotein and high-density lipoprotein in blood sera.Behavioral analysis was used to confirm the establishment of the model.Immunohistochemical methods were used to detect the expression of glial fibrillary acidic protein and nerve growth factor in the hippocampal CA1 region.The results demonstrated that,compared with the model group,blood lipid levels significantly decreased,glial fibrillary acidic protein immunoreactivity was significantly weakened and nerve growth factor immunoreactivity was significantly enhanced in the EA1 and EA2 groups.The repair effect was superior in the EA1 group than in the EA2 group.These findings confirm that EA can reduce blood lipid,inhibit glial fibrillary acidic protein expression and promote nerve growth factor expression in the hippocampal CA1 region after hyperlipidemia and middle cerebral artery thrombosis.All experimental procedures and protocols were approved by the Animal Use and Management Committee of Beijing University of Chinese Medicine,China(approval No.BUCM-3-2018022802-1002)on April 12,2018.
基金supported by the National Natural Science Foundation of China,No.81173355
文摘Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury.To further identify the involved mechanisms,we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase（MAPK） signaling pathway.We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa＇s method.At 30 minutes before model establishment,p38 MAPK blocker SB20358 was injected into the left lateral ventricles.At 1.5 hours after model establishment,electroacupuncture was administered at acupoints of Chize（LU5）,Hegu（LI4）,Zusanli（ST36）,and Sanyinjiao（SP6） for 20 minutes in the affected side.Results showed that the combination of EA and SB20358 injection significantly decreased neurologic impairment scores,but no significant differences were determined among different interventional groups.Hematoxylin-eosin staining also showed reduced brain tissue injuries.Compared with the SB20358 group,the cells were regularly arranged,the structures were complete,and the number of viable neurons was higher in the SB20358 ＋ electroacupuncture group.Terminal deoxynucleotidyl transferase（Td T）-mediated d UTP nick-end labeling assay showed a decreased apoptotic index in each group,with a significant decrease in the SB20358 ＋ electroacupuncture group.Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 ＋ electroacupuncture group compared with the ischemia/reperfusion group.There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group.These findings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway.A time period of 3 days could promote the repair of ischemic cerebral nerves.
基金Supported by Department of Science&Technology of He-bei Province(No.06276102D-31)Department of Health of Hebei Province(No.2005156)Training Program for Backbone of Scientific Research Talents of Hebei Medical University(2007)
文摘OBJECTIVE:This work aims to observe the effects of electroacupuncture on brain-derived neuro-trophic factor(BDNF)mRNA expression in mouse hippocampus following cerebral ischemia-reperfu-sion injury.METHODS:The models of mouse cerebral isch-emia-reperfusion injury were established.A total of 96 healthy mice were randomly assigned into 4 groups,namely,the sham surgery,model,mod-el+electroacupuncture,and mode+hydergine groups.Mice in the model+electroacupuncturegroup were treated through electroacupuncture at the Shenshu(BL 23),Geshu(BL 17),and Baihui(GV 20)acupoints.Mice in the model+hydergine group were intragastrically administered with hy-dergine(0.77 mg/kg-1.day-l).The levels of BDNF mRNA expressions in the hippocampus were ana-lyzed through a semi-quantitative reverse transcrip-tion-polymerase chain reaction assay on days 1 and 7 after the surgeries.RESULTS:BDNF mRNA expressions in the mouse hippocampus of the model group on days 1 and 7 after the surgery were higher than those of the sham surgery group(both P〈0.01).On days 1 and 7 of the electroacupuncture treatment,BDNF mRNA expression in the mouse hippocampus of the mod-el+electroacupuncture group was significantly ele-vated compared with the model group(both P〈0.01)or the model+hydergine group(both P〈0.01).On days 1 and 7 of the hydergine treatment,BDNF mRNA expression in the mouse hippocam-pus of the model+hydergine group tended to in-crease compared with the model group;however,statistical significance was not achieved(both P〉0.05).CONCLUSION:Electroacupuncture treatment en-hances endogenous BDNF expression,which may improve the survival environment for intracerebral neurons and inhibit the apoptosis of hippocampal cells.
基金supported by FIS/IMSS project No.FIS/IMSS/PROT/G13/1216COFAA+1 种基金SIP-IPNby DGAPA-UNAM IN203616
文摘Aging is a key risk factor for cognitive decline and age-related neurodegenerative disorders. Also, an age-related decrease in sex steroid hormones may have a negative impact on the formation of neurofibrillary tangles （NFTs）; these hormones can regulate Tau phosphorylation and the principal kinase GSK3β involved in this process. Hormone replacement therapy decreases NFTs, but it increases the risk of some types of cancer. However, other synthetic hormones such as tibolone （TIB） have been used for hormone replacement therapy. The aim of this work was to evaluate the long-term effects of TIB （0.01 mg/kg and 1mg/kg, intragastrically for 12 weeks） on the content of total and hyperphosphorylated Tau （PHF-1） proteins and the regulation of GSK3β/Akt/PI3K pathway and CDK5/p35/p25 complexes in the hippocampus of aged male mice. We observed that the content of PHF-1 decreased with TIB administration. In contrast, no changes were observed in the active form of GSK3β or PI3K. TIB decreased the expression of the total and phosphorylated form of Akt while increased that of p110 and p85. The content of CDK5 was differentially modified with TIB： it was increased at low doses and decreased at high doses. When we analyzed the content of CDK5 activators, an increase was found on p35; however, the content of p25 decreased with administration of low dose of TIB. Our results suggest a possible mechanism of action of TIB in the hippocampus of aged male mice. Through the regulation of Tau and GSK3β/Akt/PI3K pathway, and CDK5/p35/p25 complexes, TIB may modulate neuronal plasticity and regulate learning and memory processes.
