Acteoside Attenuates Recognition Memory Impairment in CUMS Rats via Regulating Synaptic Plasticity and mTOR Signaling Pathway / El Acteoside Atenúa el Deterioro de la Memoria de Reconocimiento en Ratas ELCI Mediante la Regulación de la Plasticidad Sináptica y la Vía de Señalización mTOR

SUMMARY: We evaluated the role and mechanism of acteoside in the regulation of memory impairment induced by chronic unpredictable mild stress (CUMS). CUMS was used to induce depression in rats and the successful establishment of CUMS model were verified by forced swimming test and sucrose preference test. The Y-maze test and novel object recognition test assessed memory functions. The structural changes in the cortex and hippocampus were observed by hematoxylin and eosin (HE) staining. Immunofluorescence staining and western blotting determined the protein levels. Y-maze test and novel object recognition test showed that there was memory performance impairment in rats of CUMS group, which was improved by the acteoside treatment. HE staining showed that CUMS exposure damaged the structure in the cortex and hippocampus, while the acteoside treatment alleviated the structural changes. Compared with the control group, the levels of BNDF and CREB in the cortex and hippocampus of the CUMS group were significantly decreased. Acteoside significantly reversed the expressions of these proteins in CUMS rats. Meanwhile, compared with the control group, the levels of p-mTOR and p- P70S6K in the cortex and hippocampus of the CUMS group were significantly increased, and these changes were significantly reversed by acteoside. Nevertheless, the effect of acteoside on mTOR signaling was markedly blocked by rapamycin, a specific inhibitor of mTOR signaling. Acteoside can attenuate memory impairment and ameliorate neuronal damage and synaptic plasticity in depression rats probably via inhibiting the mTOR signaling pathway. Acteoside may serve as a novel reagent for the prevention of depression.

Evaluamos el papel y el mecanismo del acteoside en la regulación del deterioro de la memoria inducido por estrés leve crónico impredecible (ELCI). Se utilizó ELCI para inducir depresión en ratas y el establecimiento exitoso del modelo ELCI se verificó mediante una prueba de natación forzada y una prueba de preferencia de sacarosa. La prueba del laberinto en Y y la prueba de reconocimiento de objetos novedosos evaluaron las funciones de la memoria. Los cambios estructurales en la corteza y el hipocampo se observaron mediante tinción con hematoxilina y eosina (HE). La tinción por inmunofluorescencia y la transferencia Western determinaron los niveles de proteína. La prueba del laberinto en Y y la prueba de reconocimiento de objetos novedosos mostraron que había un deterioro del rendimiento de la memoria en ratas del grupo ELCI, que mejoró con el tratamiento con acteósidos. La tinción con HE mostró que la exposición a ELCI dañó la estructura de la corteza y el hipocampo, mientras que el tratamiento con actósidos alivió los cambios estructurales. En comparación con el grupo de control, los niveles de BNDF y CREB en la corteza y el hipocampo del grupo ELCI disminuyeron significativamente. Acteoside revirtió significativamente las expresiones de estas proteínas en ratas ELCI. Mientras tanto, en comparación con el grupo control, los niveles de p-mTOR y p-P70S6K en la corteza y el hipocampo del grupo ELCI aumentaron significativamente, y estos cambios fueron revertidos significativamente ELCI por el acteoside. Sin embargo, el efecto del acteoside sobre la señalización de mTOR fue notablemente bloqueado por la rapamicina, un inhibidor específico de la señalización de mTOR. El acteoside puede atenuar el deterioro de la memoria y mejorar el daño neuronal y la plasticidad sináptica en ratas con depresión, probablemente mediante la inhibición de la vía de señalización mTOR. Acteoside puede servir como un reactivo novedoso para la prevención de la depresión.

Sex difference effects of acute starvation on excitatory and inhibitory synapses on dopamine neurons

Background: The aim of this study is to assess the influence of acute fasting on synaptic properties in the ventral tegmental area (VTA) with regards to the sex-dependent differences by use of male and female mice. The study aimed to unravel the intricate interplay between fasting, synaptic plasticity, and behavioural changes to enhance our understanding of the underlying mechanisms. Methods: This study carried out at a tertiary care centre, employed a 16-hour overnight fasting protocol in female rodents and male rodents to examine the effects on physiological parameters, feeding behaviour, and neuronal attributes in the VTA. Various assays, including measurements of blood glucose, ketones, corticosterone (CORT) levels, locomotor activity, and electrophysiological recordings of synaptic currents, were conducted to assess the physiological and synaptic responses to acute fasting. Results: The study found that acute fasting induced significant metabolic changes, including body mass decrease by about 10%. Altered food-seeking behaviour was evident, with male mice exhibiting a pronounced increase. Moreover, neuronal attributes in the midbrain or VTA showed gender-dependent responses: males displayed substantial 20% increase in the frequency of mEPSC onto the dopaminergic neurons in the midbrain post fasting, while females exhibited a 13% elevation in CORT levels, accompanied by a transient period of depression at stimulatory synapses onto dopaminergic neurons which was mediated by endocannabinoids. Notably, no significant changes were observed at restraining synapses in rodents of both genders. These findings highlight the nuanced influence of short-term fasting/starvation on the VTA's synaptic plasticity, emphasizing sex-specific responses and providing valuable insights into potential mechanisms influencing gender differences in neuropsychiatric conditions. Conclusions: The study reveals that acute fasting induces sex-specific synaptic changes in the VTA, shedding light on the intricate relationship between metabolism, food-seeking behaviour, and neural plasticity. These findings emphasize the importance of considering gender-specific responses in studies exploring the neurobiological effects of fasting and their relevance to mental health.

Effects of electroacupuncture with"Zhi San Zhen"on Notch signaling pathway and synaptic plasticity in 5xFAD mice / 中国组织工程研究

BACKGROUND:Alzheimer's disease is a degenerative neurological disorder characterized primarily by cognitive impairment.Acupuncture is a kind of traditional Chinese medicine therapy for treating Alzheimer's disease,but its mechanism is not yet clear. OBJECTIVE:To observe the effects of electroacupuncture with"Zhi San Zhen"on the Notch signaling pathway,β-amyloid protein(Aβ)and synaptic plasticity in 5xFAD mice. METHODS:Sixteen male,6-month-old 5xFAD mice,SPF-grade,were randomly divided into the electroacupuncture with"Zhi San Zhen"group(electroacupuncture group)and the model group,with eight mice in each group.Eight SPF-grade,male,6-month-old C57BL/6 mice were used as the wild control(wild)group.The electroacupuncture group received electroacupuncture with"Zhi San Zhen"intervention,5 times a week for 4 consecutive weeks.The model group and the wild group did not receive electroacupuncture intervention.The Morris water maze was used to preliminarily assess their learning and memory abilities.Thioflavin S staining was performed to detect Aβ plaque deposition.Western blot and real-time quantitative polymerase chain reaction(RT-qPCR)were used to measure the expression levels of transmembrane receptor protein Notch-1,Notch 1 intracellular domain(NICD),hairy and enhancer of split 1(Hes 1),hairy and enhancer of split 5(Hes 5),synaptophysin(SYN),postsynaptic density protein-95(PSD-95),and Aβ. RESULTS AND CONCLUSION:Compared with the model group,the wild group and the electroacupuncture group showed shortened escape latency,increased platform crossing times,and longer target quadrant dwell time(P<0.05).Compared with the wild group,the model group had significantly increased deposition of Aβ plaques,while electroacupuncture with"Zhi San Zhen"inhibited the deposition of Aβ plaques in the hippocampus of 5xFAD mice(P<0.05).Compared with the wild group,the model group had decreased mRNA levels of SYN,PSD-95,Notch 1,NICD,Hes 1,and Hes 5 in the hippocampal tissue of mice,and increased mRNA levels of Aβ(P<0.05).Electroacupuncture with"Zhi San Zhen"increased the mRNA levels of SYN,PSD-95,Notch 1,NICD,Hes 1,and Hes 5 in the hippocampal tissue,and decreased the mRNA level of Aβ(P<0.05).Compared with the Wild group,the model group had decreased protein expression levels of SYN,PSD-95,Notch 1,NICD,Hes 1,and Hes 5 in the hippocampal tissue of mice,and increased protein expression levels of Aβ(P<0.05).Electroacupuncture with"Zhi San Zhen"upregulated the protein expression levels of SYN,PSD-95,Notch 1,NICD,Hes 1,and Hes 5,and inhibited the protein expression of Aβ(P<0.05).To conclude,electroacupuncture with"Zhi San Zhen"can improve the learning and memory abilities of 5xFAD mice,possibly by inhibiting the deposition of Aβ protein and activating the Notch signaling pathway in the hippocampus to enhance synaptic plasticity.

Effects of aerobic exercise on learning and memory functions, hippocampal synaptic plasticity and the adiponectin signaling pathway in diabetic rats / 中华老年医学杂志

Objective:To explore the effects of aerobic exercise on learning and memory functions, hippocampal synaptic plasticity and the ADPN signaling pathway in diabetic rats.Methods:6-week-old male SD rats were randomly divided into a blank control group(NC group)and a high-fat diet group, and a rat model for diabetes was induced by feeding rats in the high-fat diet group with a high-fat diet combined with intraperitoneal instillation of low-dose streptozotocin(STZ)for 5 weeks.Rats in the high-fat diet group were further divided into a diabetic group(DC group)and a diabetic aerobic exercise group(DM group)after successful establishment of the model.Rats in the DM group were subjected to aerobic exercise for eight weeks and then the Morris water maze test was conducted to assess learning and memory functions, relevant serum markers were measured, Golgi staining was used to examine synaptic changes in the hippocampus, and Western blot was carried out to detect hippocampal protein expression levels of adiponectin(ADPN), AMP-activated protein kinase(AMPK), glucose transporter 4(GLUT4), synaptic plasticity-related protein synaptophysin(SYN)and postsynaptic density protein 95(PSD-95)for rats in each group.Results:Serum FBG and HBA1c in diabetic rats were markedly significantly decreased after 8 weeks of aerobic exercise( P<0.01), and serum ADPN and insulin were significantly increased after 8 weeks of aerobic exercise( P<0.05).When test results from the three groups of rats compared, the F value was 69.248 for FBG, 6.740 for INS, 7.017 for HBA1C and 14.315 for serum ADPN.The results of the water maze test and hippocampal Golgi staining showed that the escape latency of diabetic rats was highly significantly decreased after 8 weeks of aerobic exercise( P<0.01).The platform crossing times, the number of dendritic branches and the dendritic spine density in the hippocampal CA3 region of diabetic rats were significantly increased after 8 weeks of aerobic exercise( P<0.05).When results from the three groups of rats were compared, the F value was 13.934 for escape latency, 5.864 for platform crossing times, 9.307 and 6.734 for the number of dendritic branches and the density of dendritic spine in hippocampal CA3 region.Hippocampal PSD-95, SYN, ADPN, p-AMPK, and GLUT4 protein expression levels of diabetic rats were significantly increased( P<0.05)after 8 weeks of aerobic exercise.When results from the three groups of rats were compared, the F value was 15.137 for SYN, 5.415 for PSD-95, 9.687 for ADPN, 27.761 for GLUT4, and 9.298 for p-AMPK. Conclusions:Eight weeks of aerobic exercise can improve the learning and memory functions of diabetic rats, and the mechanisms may be related to exercise-induced hippocampal ADPN/AMPK/GLUT4 signaling activation in rats, leading to enhanced synaptic plasticity in the hippocampus.

Effects of early-life 6:2 Cl-PFESA exposure on hippocampal AMPA receptor gene expression in offspring mice / 环境与职业医学

Background The compound 6:2 chlorinated polyfluorinated ether sulfonic acids (6:2 Cl-PFESA) has been demonstrated abilities of strong bioaccumulation and placental barrier penetration, and it can also cross the blood-brain barrier. However, the mechanism of its neurodevelopmental toxicity in offspring induced by early-life exposure is still unknown. Objective To explore effects of 6:2 Cl-PFESA on the growth and the α-amino-3-hydroxy-5-methylisoxazole-4-propionic (AMPA) receptor gene expression in the hippocampus of offspring mice by establishing a 6:2 Cl-PFESA exposure animal model. Methods Thirty Kunming pregnant mice were randomly divided into five groups: control group, and 2, 10, 50, and 250 μg·L−1 6:2 Cl-PFESA exposure groups. The treatment groups were exposed to designed doses of 6:2 Cl-PFESA through drinking water from the first day of gestation until the end of lactation. The pups were weaned on postnatal day (PND) 21, and continued to be exposed to 6:2 Cl-PFESA through drinking water. Birth weight and body length of the offspring were recorded. Offspring mice were anesthetized and sacrificed respectively on PND7, PND21, and PND35, then their hippocampus was peeled from harvested brain tissue. The ultrastructure of hippocampus was observed via transmission electron microscopy; and the expression of AMPA receptors GluR1, GluR2, and GluR3 in the hippocampus was evaluated by real-time reverse transcription polymerase chain reaction. The learning and memory ability of the PND35 mice was measured by Morris water maze test before they were sacrificed. Results The birth weights and the lengths of the pups in the 10, 50, and 250 μg·L−1 6:2 Cl-PFESA exposure groups were (2.23±0.36), (1.92±0.20), (1.88±0.31) g, and (33.73±0.98), (32.91±1.30), (32.52±2.07) mm, respectively, which were lower than those in the control group, (2.78±0.35) g and (36.46±2.34) mm (P<0.05), respectively. The results of Morris water maze showed that the escape latencies in the orientation navigation experiment on the 4th day in the 250 μg·L−1 6:2 Cl-PFESA exposure group and on the 5th day in the 10, 50, and 250 μg·L−1 6:2 Cl-PFESA exposure groups were longer than those in the control group (P<0.05). In the space exploration experiment, the times of crossing platform in the 50 and 250 μg·L−1 6:2 Cl-PFESA exposure groups were decreased when compared with the control group (P<0.05), and the time of staying in the target quadrant of the 250 μg·L−1 6:2 Cl-PFESA exposure groups were also decreased (P<0.05). Via transmission electron microscopy, compared with the control group, the postsynaptic density was decreased and the synaptic cleft width was widened on PND35 in the 250 μg·L−1 6:2 Cl-PFESA exposure group. The mRNA expression levels of GluR1, GluR2, and GluR3 in the hippocampus of pups exposed to 250 μg·L−1 6:2 Cl-PFESA during different developmental stages were significantly lower than those in the control group (P<0.05). Except for the 2 μg·L−1 6:2 Cl-PFESA exposure group on PND7, the 6:2 Cl-PFESA exposure inhibited the mRNA expression levels of GluR1, GluR2, and GluR3 in the hippocampus of pups at different developmental stages (P<0.05). Among them, the 6:2 Cl-PFESA exposure during early development resulted in the highest decrease in the expression levels of GluR1 and GluR2 mRNA in the hippocampus of pups on PND7; GluR3 mRNA expression level in the hippocampus of the exposed pups on PND21 showed the maximum inhibitory effect; the expression levels of GluR1, GluR2, and GluR3 mRNA all showed the least decrease in the hippocampus of the exposure groups on PND35. Conclusion Early-life exposure to 6:2 Cl-PFESA may affect the growth and development of offspring mice, alter the hippocampal synaptic structure, and influence the learning and memory abilities, which may be related to their inhibitory effects on the expression levels of AMPA receptor subunits GluR1, GluR2, and GluR3 genes in the hippocampus of offspring mice at various developmental stages.

Hei Xiaoyaosan Affects Synaptic Plasticity of Hippocampal Neurons in APP/PS1 Double Transgenic Mice of AD via cAMP/PKA/NMDAR Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect and mechanism of Hei Xiaoyaosan in modulating the synaptic plasticity in APP/PS1 mice by regulating the cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA）/N-methyl-D-aspartate receptor （NMDAR） signaling pathway. MethodTwelve 4-month-old male C57BL/6J mice were selected as the blank control group， and 60 4-month-old male APP/PS1 double transgenic mice were randomized into model， KW-6002 （adenosine receptor antagonist， 3 mg·kg-1）， and high-， medium-， and low-dose （22.10， 11.05， 5.53 g·kg-1， respectively） Hei Xiaoyaosan groups， with 12 mice in each group. Mice were administrated with corresponding drugs for 90 days. Transmission electron microscopy was employed to observe the synaptic ultrastructure of hippocampal neurons， and Golgi staining was used to observe the dendritic spine density of neurons in hippocampal CA1 region. Western blot was employed to measure the protein levels of cAMP， PKA， N-methyl-D-aspartate receptors 1， 2A， and 2B （NR1， NR2A， and NR2B， respectively）， postsynaptic density protein 95 （PSD95）， and synapsin 1 （SYN1）. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） was performed to determine the mRNA levels of cAMP， PKA， and NR1. Enzyme-linked immunosorbent assay was employed to determine the content of interleukin-12 （IL-12） and interleukin-4 （IL-4） in the hippocampus. ResultCompared with the blank group， the model group showed blurred boundaries between presynaptic membrane and postsynaptic membrane in hippocampal CA1 region， reduced and scattered synaptic vesicles， and decreased density of postsynaptic membrane， and irregular， disarranged， and loosened dendritic spines of neurons in hippocampal CA1 region （P<0.01）. In addition， the model group presented down-regulated protein levels of cAMP， PKA， NR1， NR2A， NR2B， PSD95， and SYN1 and mRNA levels of cAMP， PKA， and NR1， elevated IL-12 level， and lowered IL-4 level in the hippocampus （P<0.01）. Compared with the model group， the drug intervention groups showed clear and intact boundaries between presynaptic membrane and postsynaptic membrane in hippocampal CA1 region， increased synaptic vesicles with dense arrangement， increased density of postsynaptic membrane， and improved morphology， arrangement， and density of neuronal dendritic spines （P<0.05， P<0.01）. In addition， the drug interventions up-regulated the protein levels of cAMP， PKA， NR1， NR2A， NR2B， PSD95， and SYN1 （P<0.05，P<0.01） and mRNA levels of cAMP， PKA， and NR1 （P<0.01）， lowered the IL-12 level （P<0.01）， and elevated the IL-4 level （P<0.01） in the hippocampus. ConclusionHei Xiaoyaosan can improve the structure and morphology of hippocampal neurons in APP/PS1 mice by activating the cAMP/PKA/NMDAR signaling pathway and repairing synaptic plasticity.

Research progress in the effectiveness and mechanism of hyperbaric oxygen therapy for depression / 四川精神卫生

Hyperbaric oxygen therapy characterized by fewer side effects and simple operation has been explored as a potential therapy for depression. This article provides a review of researches relevant to current clinical application and mechanism of hyperbaric oxygen therapy for depression， aiming to provide valuable references for the formulation of new strategies for the treatment of depression. Hyperbaric oxygen therapy has been demonstrated to be useful as an adjunctive therapy for depression， which can effectively alleviate depression by regulating the homeostasis of hypothalamus-pituitary-adrenal axis， inhibiting inflammation and enhancing synaptic plasticity. And hyperbaric oxygen therapy as adjuvant to antidepressants for depression can contribute to increasing the treatment effectiveness to some extent.

Wenyang Jieyu Prescription Regulates Hippocampal Neural Plasticity in Depressed Mice via NLRP3/Caspase-1/IL-1β Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effects of Wenyang Jieyu prescription （WJP） on neuroinflammation and synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 （PD0） were randomized into a control group and a modeling group. Maternal separation combined with restraint stress was employed to establish the mouse model of depression. After the removal of female mice， the modeled mice were randomized into model， Wenyang prescription （5.85 g·kg-1）， Jieyu prescription （12.03 g·kg-1）， WJP （16.71 g·kg-1）， and fluoxetine （2.6 mg·kg-1） groups on the weaning day （PD21）， with 15 mice in each group. The mice were administrated with corresponding drugs mixed with the diet from PD21 to PD111. The sucrose preference test， open field test， O-maze test， and novel object recognition test were then carried out to evaluate the depression state， memory， and learning ability of the mice. Immunohistochemistry （IHC） was employed to observe the ionized calcium-binding adapter molecule-1 （Iba-1） in hippocampal microglia. High performance liquid chromatography （HPLC） was employed to measure the content of noradrenaline （NE） and epinephrine （E） in the hippocampus. Enzyme-linked immunosorbent assay （ELISA） was employed to determine the content of interleukin （IL）-18 and IL-1β in the hippocampus. Western blot was employed to determine the protein levels of NOD-like receptor protein 3 （NLRP3）， apoptosis-associated speck-like protein containing a CARD （ASC）， cysteine aspartate-specific protease-1 （Caspase-1）， IL-1β， synaptophysin （Syn）， and postsynaptic density 95 （PSD95）. ResultCompared with control group， the model group showed decreased sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. The microglia in the model group presented amoeba-like appearance， the Iba1 increased. Moreover， the model group showed decreased content of NE and E （P<0.01）， elevated levels of IL-1β and IL-18 （P<0.01）， down-regulated protein levels of PSD95 and Syn （P<0.05， P<0.01）， and up-regulated protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. Compared with model group， WJP and fluoxetine increased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. They recovered the microglia and the Iba1 decreased. Moreover， the drugs increased the content of NE and E （P<0.05， P<0.01）， lowered the levels of IL-1β and IL-18 （P<0.01）， up-regulated the protein levels of PSD95 and Syn （P<0.01）， down-regulated the protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. ConclusionWJP can treat the depressive behavior induced by maternal separation combined with restraint stress in mice， with the performance outperforming Wenyang prescription and Jieyu prescription. It may alleviate the neuroinflammation induced by microglia and improve the synaptic plasticity by regulating the NLRP3 pathway and increasing neurotransmitters in the hippocampus.

Wenyang Jieyu Prescription Regulates Hippocampal Neuron Apoptosis and Improves Synaptic Plasticity in Depressed Mice via BDNF/Akt/mTOR Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Wenyang Jieyu prescription in regulating hippocampal neuron apoptosis and improving synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 （PD0） were randomly assigned into a control group （n=10） and a modeling group （n=50）. Maternal separation combined with restraint stress was adopted to establish the mouse model of depression， and the modeled mice were randomized into model， Wenyang prescription， Jieyu prescription， Wenyang Jieyu prescription， and fluoxetine groups （n=10） on the weaning day （PD21）. From PD21 to PD111， the mice were fed with the diets mixed with corresponding medicines. The sucrose preference test， open field test， O-maze test， and novel object recognition test were then conducted to evaluate the depression， memory， and learning abilities of mice. Immunohistochemistry （IHC） was employed to measure the atomic absorbance （AA） of postsynaptic density protein 95 （PSD95） in the hippocampus. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling （TUNEL） was employed to detect the apoptosis of hippocampal neurons. Western blot was employed to determine the protein levels of brain-derived neurotrophic factor （BDNF）， phosphorylated tyrosine kinase receptor B/tyrosine kinase receptor B （p-TrkB/TrkB）， phosphorylated protein kinase B/protein kinase B （p-Akt/Akt）， phosphorylated mammalian target of rapamycin/mammalian target of rapamycin （p-mTOR/mTOR）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X （Bax）， cysteinyl aspartate-specific proteinase-3 （Caspase-3）， synaptophysin （Syn）， and PSD95. ResultCompared with the control group， the modeling decreased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.01）. Furthermore， it decreased the expression of PSD95， increased the neuron apoptosis in the hippocampus （P<0.01）， down-regulated the protein levels of BDNF， p-TrkB/TrkB， p-Akt/Akt， p-mTOR/mTOR， Bcl-2， PSD95， and Syn （P<0.01）， and up-regulated the protein levels of Bax and Caspase-3 （P<0.05） in the hippocampus. Compared with the model group， Wenyang Jieyu prescription and fluoxetine increased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. Moreover， the drugs increased the expression of PSD95， reduced the neuron apoptosis （P<0.01）， up-regulated the protein levels of BDNF， p-TrkB/TrkB， p-Akt/Akt， p-mTOR/mTOR， Bcl-2， PSD95， and Syn （P<0.01）， and down-regulated the protein levels of Bax and Caspase-3 （P<0.01）. ConclusionWenyang Jieyu prescription outperformed Wenyang prescription and Jieyu prescription in the treatment of the depressive behavior induced by maternal separation combined with restraint stress in mice. It exerted the therapeutic effect by reducing the hippocampal neuron apoptosis and improving the synaptic plasticity via the BDNF/Akt/mTOR pathway.

Expression of synapse-related proteins in hippocampus of rats with epilepsy accompanied by depression / 中华行为医学与脑科学杂志

Objective:To investigate the expression of hippocampal synapse-related proteins including synaptophysin (SYN), postsynaptic density protein 95 (PSD95) and growth-associated protein 43 (GAP43) in rats with epilepsy accompanied by depression.Methods:The 3-month-old female clean grade SD rats were selected for the experiment.Lithium chloride pilocarpine was used to establish an epileptic rat model. Rats with successful epilepsy models were divided into epileptic depressive group (EWD group)and epileptic group with 10 in each group based on whether they were accompanied by depression. Furthermore, ten rats with matched body mass were taken as the depressive group and 10 were taken as control group. As for the depressive group rats, chronic unpredictable mild stress stimulation combined with orphanage was adopted to establish a model of depression.The depressive behaviors of rats were evaluated by body mass, sucrose preference test and open field test. Immunohistochemical staining and Western blot were used to detect the expression of SYN, PSD95 and GAP43 proteins in rat hippocampal tissue. SPSS 17.0 software was used for data statistical analysis, repeated measurement ANOVA was used for behavioral results, one-way ANOVA was used for inter group comparison of protein expression data, and LSD test was used for further pairwise comparison.Results:As for the body mass, there was significant interaction effect between the time and group among the 4 groups ( F=7.33, P<0.01). On the 8th day and the 29th day, the body weight of rats in the EWD group and the depressive group were lower than those in the epilepsy group (all P<0.05). The body weight of rats in the EWD group on the 29th day was lower than that on the first day ( P<0.05). As for the sucrose preference rates, there was significant interaction effect between the time and group among the 4 groups( F=2.67, P<0.05). The sucrose preference rate of EWD group on the15th and 29th day were lower than that on the first day (both P<0.05). The results of the open field test showed that the interaction effects of the number of vertical standing times( F=2.74) and the number of horizontal movement lattices ( F=1.76) both were not significant (both P>0.05), but both the time effect and group effect were significant (vertical standing times: Ftime=4.35, P<0.05, Fgroup=25.64, P<0.01; horizontal movement lattices: Ftime=12.75, P<0.01, Fgroup=21.37, P<0.01). The immunohistochemical results showed that there was a statistically significant difference in the number of positive cells expressing synaptic proteins SYN, PSD95 and GAP43 among the four groups of rats ( F=93.85, 58.66, 98.84, all P<0.05). The numbers of positive cells of SYN (11.73±4.30), PSD95 (24.47±7.58) and GAP43 (9.40±3.50) in the epilepsy group were lower than those in the control group ((51.00±15.39), (55.60±13.17) and (29.53±4.05)) (all P<0.05). The numbers of positive cells of SYN (5.80±3.53), PSD95 (12.87±4.03) and GAP43 (5.33±3.50) in the EWD group were lower than those in the depressive group ((11.33±3.22), (48.13±12.69) and (15.47±5.21) )(all P<0.05). Western blot results showed that there were statistically significant differences in the expression of synaptic proteins SYN, PSD95 and GAP43 among the four groups of rats ( F=13.19, 9.38, 16.80, all P<0.05). The expression levels of SYN, PSD95 and GAP43 in the epilepsy group were lower than those in the control group (all P<0.05). The expression levels of SYN, PSD95 and GAP43 in the EWD group were lower than those in the epilepsy group and the depressive group (all P<0.05). Conclusion:The low expression of SYN, PSD95 and GAP43 proteins in the hippocampus of rats with epilepsy accompanied by depression may be related to their pathogenesis.

Effects of icariin on BDNF/TkB signaling pathway and synaptic plasticity regulation on fear memory improvement in rats with post-traumatic stress disorder / 中国医科大学学报

Objective To investigate the effects and mechanisms of icariin on changes in fear memory in post-traumatic stress disorder(PTSD)rats.Methods Thirty male SD rats were used to construct a rat model of single prolonged stress(SPS).The model rats were randomly divided into the SPS,icariin,and icariin + K252a(tyrosine kinase receptor B inhibitor)groups(n= 10 each;another 10 normal rats were used as the control group).The icariin and icariin + K252a groups were administered 20 mg/kg icariin by gavage once per day after SPS,while the control and SPS groups were administered the same dose of normal saline.K252a cells were injected into the lateral ventricles.After 2 weeks,anxiety,depression,and fear memory disorder in rats in each group were detected by the mine experiment,ele-vated cross maze experiment,and conditional fear test.The binding activity of icariin to brain-derived neurotrophic factor(BDNF)and the BDNF and TrkB expressions in the rat amygdala were detected by immunohistochemistry.The relative expressions of BDNF and TrkB pro-teins were detected by Western blotting.The expressions of postsynaptic density protein 95(PSD95)and synaptophysin(SYN)in the rat amygdala were detected using immunofluorescence.Results Icariin showed strong binding to BDNF.Compared with the control group,the times of entering the central area and the percentage of movement distance in the central area in the SPS group and the icariin+K252a group were significantly reduced.The open arm entry(OE)and arm opening time(OT)were significantly reduced,the freezing time and defecation times were significantly increased,and the expressions of the BDNF,TrkB,PSD95,and SYN proteins were significantly reduced(P<0.05).Compared with the SPS group,the icariin group rats had significantly increased times of entering the central area and percentages of movement distance in the central area,significantly increased OE and OT,significantly reduced the time of immobilization and defecation,and significantly increased the expressions of BDNF,TrkB,PSD95,and SYN proteins(P<0.05).Conclusion Icariin effectively alleviated the fear memory impairment induced by SPS in rats.This protective effect is related to BDNF/TrkB signaling pathway activation and upregulated PSD95 and SYN expression.

Effects of the 5-HT1A receptor antagonist on synaptic plasticity in sevoflurane-induced cognitive dysfunction in aged rats and its mechanism / 中国医科大学学报

Objective To investigate the effect of the 5-HT1A receptor antagonist on synaptic plasticity in flurane-induced cognitive dys-function in aged rats.Methods Thirty 18-month-old Sprague-Dawley rats were randomly divided into control,model,and drug groups.The model group inhaled a 50%oxygen gas mixture(2 L/min)and 2%sevoflurane and were then treated with 5μL 0.9%NaCl;the drug group inhaled a 50%oxygen mixture(2 L/min)and 2%sevoflurane for 4 h and then the 5-HT1A receptor antagonist(3μg)was injected into the left ventricles of the rats;and the control group inhaled a 50%oxygen mixture(2 L/min)for 4 h.The water maze method was used to assess the learning memory of the rats and histopathological changes in the rat hippocampus were examined by HE staining.Nissl and Golgi staining were used to identify any changes to the neurons and synapses in hippocampal tissue.The MeCP2,p250GAP,PSD-95,GAP-43,and Syn expression levels were determined by immunofluorescence assay and the PKA,CREB1,and BDNFmRNA levels were determined using real-time PCR.Western blotting was performed to determine the PKA,CREB1,p-CREB1,and BDNF expression levels.Results The water maze data showed that the escape latency was significantly prolonged in the model group compared to the control group and,after treatment with the 5-HT1A receptor antagonist,the escape latency significantly decreased in the drug group compared to that of the model group(P<0.05).Moreover,the number of platform crossings was significantly lower in the model group than in the control group,but the number of platform crossings in the drug group was significantly higher than that in the model group(P<0.05).Compared to the control group,the hippocampal neurons in the model group had irregular morphology,loosely arranged and enlarged sur-rounding tissue gaps,deeply stained nuclei,a reduced number of Nissl bodies in the neurons,and a significantly reduced dendritic spine density and number of branches.After treatment with the 5-HT1A receptor antagonist,the hippocampal neurons in the drug group had a regular morphology,relatively complete structure,uniform arrangement,increased numbers of Nissl bodies in the neurons,and a signifi-cantly increased dendritic spine density and number of dendritic branches.Compared to the control group,MeCP2,PSD-95,GAP-43,Syn,PKA,CREB1,p-CREB1,and BDNF expression levels significantly decreased and p250GAP expression significantly increased in the rat brain tissue from the model group(P<0.05),but the PKA,CREB1,and BDNF mRNA levels significantly decreased(P<0.05).Furthermore,compared to the model group,the MeCP2,PSD-95,GAP-43,Syn,PKA,CREB1,p-CREB1,and BDNF expres-sion levels significantly increased along with the PKA,CREB1,and BDNF mRNA levels(P<0.05)in the drug group.However,the p250GAP protein expression level significantly decreased(P<0.05).Conclusion The 5-HT1A receptor antagonist improves learning memory in rats with sevoflurane-induced cognitive dysfunction.Specifically,it enhances PSD-95,GAP-43,and Syn expression levels,pro-motes synaptic remodeling,and protects rat hippocampal neuronal cells by activating the CREB/BDNF pathway.

Research progress in astrocyte dysfunction and depression / 中国药理学与毒理学杂志

Most of the current research on depression focuses on neuronal regulation,while the astrocytic mechanism of depression is far from explored.Astrocytes are the most numerous and widely distributed glial cells in the central nervous system.With a complex structural morphology,astrocytes play an important role in a variety of neuropsychiatric disorders by interacting with neuronal synapses,vasculature and other glial cells.Recent studies have shown that astrocytes may be involved in depression by regulating monoamine transmitters,glutamate cycle,synaptic plasticity,energy metabo-lism,and neuroinflammation.This review is intended to inspire new ideas for the treatment of depres-sion and the development of novel drugs based on astrocyte regulation.

Action mechanism of vinpocetine in improving learning and memory disorders in depressive rats after MECT / 西安交通大学学报(医学版)

【Objective】 To explore the action mechanism of vinpocetine in improving learning and memory disorders in depressive rats after modified electroconvulsive therapy (MECT). 【Methods】 The models of depressive rats were constructed by chronic unpredictable mild stress (CUMS) method. A total of 30 rats with depression were randomly divided into depression group, MECT group, and MECT+vinpocetine (10 mg/kg) group, with 10 in each group. A total of 10 untreated healthy rats were enrolled as control group. The learning and memory ability were tested by Morris water maze test and novel object recognition test. The depression state was evaluated by sugar preference test. The brain slices of the hippocampus were prepared for electrophysiological experiments. The density of dendritic spine was detected by Golgi staining. The expressions of endocannabinoids related genes [diacylglycerol lipase (DAGLα), monoacylglycerol lipase (MAGL), and endocannabinoid type-I receptor (CB1R)] were detected by qPCR and Western blotting. The lentivirus was injected to downregulate the expressions of CB1R and DAGLα in the hippocampus. After re-modeling and treatment, behavioral tests were performed. 【Results】 Compared with control group, sugar preference, spatial exploration time, relative discrimination index, long-term potentiation (LTP), density of dendritic spine, expressions of DAGLα and CB1R were decreased, while escape latency and MAGL were increased in depression group (P<0.05). Compared with depression group, sugar preference, escape latency, and MAGL were increased, while spatial exploration time, relative discrimination index, LTP, density of dendritic spine, expressions of DAGLα and CB1R were decreased in MECT group (P<0.05). Compared with depression group, sugar preference, spatial exploration time, relative discrimination index, LTP, density of dendritic spine, expressions of DAGLα and CB1R were increased, while escape latency and MAGL were decreased in MECT+vinpocetine group (P<0.05). Compared with MECT group, sugar preference, spatial exploration time, relative discrimination index, LTP, density of dendritic spine, expressions of DAGLα and CB1R were increased, while escape latency and MAGL were decreased in MECT+vinpocetine group (P<0.05). The down-regulation of DAGLα or CB1R by lentivirus could inhibit the improvement effect of vinpocetine on behavioral performance of depressive rats after MECT. 【Conclusion】 Vinpocetine can significantly improve learning and memory disorders in depressive rats after MECT, which may be related to regulating the expressions of endocannabinoid-related genes and enhancing synaptic plasticity.

Effect of Xiaoxuming Decoction on synaptic plasticity following acute cerebral ischemia-reperfusion in rats / 中国中药杂志

This study aims to explore the effect of Xiaoxuming Decoction on synaptic plasticity in rats with acute cerebral ischemia-reperfusion. A rat model of cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion(MCAO). Rats were randomly assigned into a sham group, a MCAO group, and a Xiaoxuming Decoction(60 g·kg~(-1)·d~(-1)) group. The Longa score was rated to assess the neurological function of rats with cerebral ischemia for 1.5 h and reperfusion for 24 h. The 2,3,5-triphenyltetrazolium chloride(TTC) staining and hematoxylin-eosin(HE) staining were employed to observe the cerebral infarction and the pathological changes of brain tissue after cerebral ischemia, respectively. Transmission electron microscopy was employed to detect the structural changes of neurons and synapses in the ischemic penumbra, and immunofluorescence, Western blot to determine the expression of synaptophysin(SYN), neuronal nuclei(NEUN), and postsynaptic density 95(PSD95) in the ischemic penumbra. The experimental results showed that the modeling increased the Longa score and led to cerebral infarction after 24 h of ischemia-reperfusion. Compared with the model group, Xiaoxuming Decoction intervention significantly decreased the Longa score and reduced the formation of cerebral infarction area. The modeling led to the shrinking and vacuolar changes of nuclei in the brain tissue, disordered cell arrangement, and severe cortical ischemia-reperfusion injury, while the pathological damage in the Xiaoxuming Decoction group was mild. The modeling blurred the synaptic boundaries and broadened the synaptic gap, while such changes were recovered in the Xiaoxuming Decoction group. The modeling decreased the fluorescence intensity of NEUN and SYN, while the intensity in Xiaoxuming Decoction group was significantly higher than that in the model group. The expression of SYN and PSD95 in the ischemic penumbra was down-regulated in the model group, while such down-regulation can be alleviated by Xiaoxuming Decoction. In summary, Xiaoxuming Decoction may improve the synaptic plasticity of ischemic penumbra during acute cerebral ischemia-reperfusion by up-regulating the expression of SYN and PSD95.

Shouwuwan Regulates Synaptic Plasticity of Hippocampal Neurons in Rat Model of D-galactose-induced Aging via mTOR Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Shouwuwan on the synaptic plasticity of hippocampal neurons in the rat model of D-galactose-induced aging via the mammalian target of rapamycin （mTOR） signaling pathway. MethodA total of 50 male SPF-grade SD rats were randomized into normal group， model group， vitamin E （0.018 g·kg-1） group， and low- and high-dose （1.08，2.16 g·kg-1， respectively） Shouwuwan groups. Except the normal group， the other four groups were treated with D-galactose （120 mg·kg-1） for the modeling of aging. The rats were simultaneously administrated with corresponding agents by gavage. After six weeks of modeling， Morris water maze test was carried out to examine the behavioral changes. The whole brain and hippocampus samples were collected. The expression of postsynaptic density protein-95 （PSD-95） and synaptophysin （SYN） in the hippocampus was detected by immunohistochemistry. Golgi staining was employed to observe the changes in the morphology and function of neurons. Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） were respectively employed to determine the mRNA and protein levels of mTOR， phosphorylated （p）-mTOR， p70 ribosome protein S6 kinase （p70S6K）， phosphorylated （p）-p70S6K， eukaryotic translation initiation factor 4E-binding protein 2 （4EBP2）， and phosphorylated （p）-4EBP2 in the hippocampus. ResultCompared with the normal group， the model group showed slow swimming （P<0.01）， extended total swimming distance （P<0.05）， prolonged latency （P<0.01）， and decreased crossing number （P<0.01）. The modeling inhibited the expression of PSD-95 and SYN in the CA1 region of the hippocampus （P<0.01）， with the weakest staining effect and the smallest region， decreased the intersections of hippocampal neuron dendrites with concentric circles at the concentric distance of 100， 140， 180， and 200 μm from the cell body （P<0.01）， and reduced the length and density of dendritic spine （P<0.01）. In addition， the modeling up-regulated the mRNA levels of mTOR and p70S6K and the protein levels of p-mTOR and p-p70S6K （P<0.01） and down-regulated the mRNA level of 4EBP2 and the protein levels of 4EBP2 and p-4EBP2 （P<0.01）. Compared with the model group， low- and high-dose Shouwuwan increased the average swimming speed （P<0.01）， shortened the latency （P<0.01）， increased the crossing number （P<0.01）， promoted the expression of PSD-95 and SYN in the hippocampal CA1 region （P<0.01）， increased the intersections between hippocampal neuronal dendrites and concentric circles at the concentric distance of 100， 140， 180，200 μm from the cell body （P<0.01）， and increased the number， length， and density of dendritic spine （P<0.01）. Furthermore， Shouwuwan down-regulated the protein levels of p-mTOR and p-p70S6K （P<0.01）， up-regulated the protein levels of 4EBP2 and p-4EBP2 （P<0.05，P<0.01）， down-regulated the mRNA levels of mTOR and p70S6K （P<0.01）， and up-regulated the mRNA level of 4EBP2 （P<0.01）. ConclusionShouwuwan can improve the learning and memory ability of rats exposed to D-galactose， promote the expression of proteins associated with synaptic plasticity， improve the morphology of neurons， repair neural function， reduce neuronal apoptosis， and inhibit mTOR signaling pathway to delay brain aging.

Disrupted Maturation of Prefrontal Layer 5 Neuronal Circuits in an Alzheimer's Mouse Model of Amyloid Deposition / 神经科学通报·英文版

Mutations in genes encoding amyloid precursor protein (APP) and presenilins (PSs) cause familial forms of Alzheimer's disease (AD), a neurodegenerative disorder strongly associated with aging. It is currently unknown whether and how AD risks affect early brain development, and to what extent subtle synaptic pathology may occur prior to overt hallmark AD pathology. Transgenic mutant APP/PS1 over-expression mouse lines are key tools for studying the molecular mechanisms of AD pathogenesis. Among these lines, the 5XFAD mice rapidly develop key features of AD pathology and have proven utility in studying amyloid plaque formation and amyloid β (Aβ)-induced neurodegeneration. We reasoned that transgenic mutant APP/PS1 over-expression in 5XFAD mice may lead to neurodevelopmental defects in early cortical neurons, and performed detailed synaptic physiological characterization of layer 5 (L5) neurons from the prefrontal cortex (PFC) of 5XFAD and wild-type littermate controls. L5 PFC neurons from 5XFAD mice show early APP/Aβ immunolabeling. Whole-cell patch-clamp recording at an early post-weaning age (P22-30) revealed functional impairments; although 5XFAD PFC-L5 neurons exhibited similar membrane properties, they were intrinsically less excitable. In addition, these neurons received smaller amplitude and frequency of miniature excitatory synaptic inputs. These functional disturbances were further corroborated by decreased dendritic spine density and spine head volumes that indicated impaired synapse maturation. Slice biotinylation followed by Western blot analysis of PFC-L5 tissue revealed that 5XFAD mice showed reduced synaptic AMPA receptor subunit GluA1 and decreased synaptic NMDA receptor subunit GluN2A. Consistent with this, patch-clamp recording of the evoked L23>L5 synaptic responses revealed a reduced AMPA/NMDA receptor current ratio, and an increased level of AMPAR-lacking silent synapses. These results suggest that transgenic mutant forms of APP/PS1 overexpression in 5XFAD mice leads to early developmental defects of cortical circuits, which could contribute to the age-dependent synaptic pathology and neurodegeneration later in life.

Bidirectional mechanism of comorbidity of depression and insomnia based on synaptic plasticity / 中南大学学报(医学版)

Insomnia is one of the most common accompanying symptoms of depression,with both sharing highly overlapping molecular pathways.The same pathological changes can trigger comorbidity of insomnia and depression,which further forms a vicious cycle with the involvement of more mechanisms and disease progression.Thus,understanding the potential interaction mechanisms between insomnia and depression is critical for clinical diagnosis and treatment.Comorbidity genetic factors,the hypothalamic-pituitary-adrenal axis,along with circadian rhythms of cortisol and the brain reward mechanism,are important ways in contributing to the comorbidity occurrence and development.However,owing to lack of pertinent investigational data,intricate molecular mechanisms necessitate further elaboration.Synaptic plasticity is a solid foundation for neural homeostasis.Pathological alterations of depression and insomnia may perturb the production and release of neurotransmitter,dendritic spine remodeling and elimination,which converges and reflects in aberrant synaptic dynamics.Hence,the introduction of synaptic plasticity research route and the construction of a comprehensive model of depression and insomnia comorbidity can provide new ideas for clinical depression insomnia comorbidity treatment plans.

Protective effects of the salt-induced kinase inhibitor HG-9-91-01 on sepsis-associated cognitive dysfunction in mice and the underlying mechanisms / 中南大学学报(医学版)

Objective:Sepsis-associated cognitive dysfunction is a common complication in patients with sepsis and lack of effective treatment.Its pathological mechanisms remain unclear.Salt-induced kinase(SIK)is an important molecule in the regulation of metabolism,immunity,and inflammatory response.It is associated with the development of many neurological diseases.This study aims to investigate the expression of SIK in the hippocampus of septic mice,and to evaluate the role and mechanism of the SIK inhibitor HG-9-91-01 in sepsis-associated cognitive dysfunction. Methods:Firstly,C57BL/6 mice were randomly divided into a control group(Con group)and a sepsis model group[lipopolysaccharide(LPS)group].The model group was injected intraperitoneally with LPS at a dose of 8 mg/kg and the Con group was injected with an equal volume of normal saline.Hippocampal tissues were harvested at 1,3,and 6 days after injection and the expressions of SIK1,SIK2,and SIK3 were detected by real-time fluorescence quantitative PCR(qPCR)and Western blotting.Secondly,C57BL/6 mice were randomly divided into a Con group,a LPS group,and a SIK inhibitor group(HG group).The LPS and HG groups were injected with LPS to establish a sepsis model;in the HG group,HG-9-91-01(10 mg/kg)was injected intraperitoneally at 3-6 days after LPS injection,and the LPS group was injected with the same volume of vehicle.Cognitive function was assessed at 7-11 days after LPS injection using the Morris water maze(MWM).Hippocampal tissues were harvested after the behavioral tests,and the mRNA levels of inflammatory factors and microglial markers were assessed by qPCR.The protein levels of inducible nitric oxide synthase(iNOS),CD68,ionized calcium binding adaptor molecule 1(Iba-1),N-methyl-D-aspartate(NMDA)receptor(NR)subunit,cAMP response element-binding protein(CREB)-regulated transcription coactivator 1(CRTC1),and insulin-like growth factor 1(IGF-1)were detected by Western blotting.Immunohistochemistry(IHC)was used to detect the expression of Iba-1 positive cells in the CA1,CA3 and dentate gyrus(DG)of the hippocampus,followed by Sholl analysis. Results:Compared with the Con group,the mRNA and protein levels of SIK1,SIK2,and SIK3 in the hippocampus were increased in the LPS group(all P<0.05).Compared with the Con group,mice in the LPS group had a significantly longer escape latency,a lower percentage of target quadrant dwell time and a reduced locomotor speed(all P<0.05);the HG group had a decreased escape latency and an increased percentage of time spent in the target quadrant in comparison with the LPS group(both P<0.05).The mRNA levels of inflammatory factors[tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6)],and the M1-type microglial markers iNOS and CD68 in the hippocampus of the LPS group were increased in comparison with the Con group,while the M2-type microglial markers CD206 and arginase-1(Arg-1)were decreased.Compared with the LPS group,the mRNA levels of TNF-α,IL-1β,IL-6,and iNOS were downregulated,while the levels of CD206 and Arg-1 were upregulated in the HG group(all P<0.05).The protein levels of iNOS,CD68,and Iba-1 in the hippocampus of the LPS group were increased in comparison with the Con group,but they were downregulated in the HG group in comparison with the LPS group(all P<0.05).The number of Iba-1 positive cells in CA1,CA3,and DG of the hippocampus was increased in the LPS group in comparison with the Con group,but they were decreased in the HG group in comparison with the LPS group(all P<0.05).Sholl analysis showed that the number of intersections at all radii between 8-38 μm from the microglial soma was decreased in the LPS group in comparison with the Con group(all P<0.05).Compared with the LPS group,the number of intersections at all radii between 14-20 μm was significantly increased in the HG group(all P<0.05).The protein levels of NR subunit NR1,NR2A,NR2B,and IGF-1 were downregulated in the hippocampus of the LPS group in comparison with the Con group,while the expression of phosphorylated CRTC1(p-CRTC1)was increased.Compared with the LPS group,the levels of NR1,NR2A,NR2B,and IGF-1 were upregulated,while p-CRTC1 was downregulated in the HG group(all P<0.05). Conclusion:SIK expression is upregulated in the hippocampus of septic mice.The SIK inhibitor HG-9-91-01 ameliorates sepsis-associated cognitive dysfunction in mice,and the mechanism may involve in the activation of the CRTC1/IGF-1 pathway,inhibition of neuroinflammation,and enhancement of synaptic plasticity.

Effect of Median Nerve Electrical Stimulation on Synaptic Plasticity in Ischemic Stroke Rats / 昆明医科大学学报

Objective To investigate the effects and mechanisms of median nerve electrical stimulation on synaptic plasticity in ischemic stroke rats.Methods 18 healthy male SD rats were randomly divided into Sham group(n = 6),ischemic stroke group(MCAO group,n = 6)and median nerve electrical stimulation group(MNES group,n = 6).The left middle cerebral artery occlusion model of rats was established by thread plug method.Thread plug was not inserted in sham group.The median nerve electrical stimulation group was given median nerve electrical stimulation intervention on the 3rd day after modeling,and intervention on the next day.After intervention for 7 times,behavioral detection,HE staining was used to detect median nerve injury.Nissl staining was used to detect cerebral infarction volume.Western blot was used for detection of the expression level of proteins related to synaptic plasticity,and electron microscopy was performed.Results HE staining showed that median nerve electrical stimulation did not cause damage to the median nerve in stroke rats,and the median nerve membrane was intact without obvious inflammatory cells.Compared with MCAO group,the neural function,motor function and coordination of the injured forelimb in MNES group were significantly improved(P<0.01).Compared with MCAO group,cerebral infarction volume in MNES group was significantly reduced(P<0.05),the pyknosis of Nissl bodies in ischemic penumbra decreased.Compared with MCAO group,the expression levels of synaptic plastication-related proteins PSD95 and synI in the cortex of MNES group were significantly up-regulated after median nerve electrical stimulation(P<0.05),the number of synapses in the ischemic cortex increased significantly(P<0.01).Conclusion Median nerve electrical stimulation is a safe and effective therapeutic measure to improve nerve function after stroke,and its mechanism is related to promoting synaptic plasticity.