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.

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.

Effect of Xiaoxuming decoction on OGD/R-induced synaptic plasticity in HT22 cells / 中国病理生理杂志

AIM:To explore the protective effect of Xiaoxuming decoction(XXMD)on synaptic plasticity in the context of cerebral ischemia-reperfusion injury following ischemic stroke.METHODS:An oxygen-glucose depriva-tion/reoxygenation(OGD/R)model was employed in vitro using mouse hippocampal neurons(HT22 cells)to simulate ischemia-reperfusion injury.Cell viability was assessed using a CCK-8 assay to determine the optimal XXMD concentra-tion.The HT22 cells were divided into two groups:control and model(OGD/R).Cellular morphological changes were ob-served using an inverted microscope.The levels of IL-1β,IL-6 and TNF-α in the supernatant were quantified by ELISA.Ultrastructural changes were examined by transmission electron microscopy.Immunofluorescence staining was used to de-tect neuron markers NeuN and synaptic proteins NF200 and MAP2.The protein levels of NF200 and MAP2 were analyzed by Western blot.RESULTS:The highest cell survival rate occurred at an XXMD concentration of 100 mg/L(P<0.05).Compared with control group,the cells in model group exhibited round shape and shrinkage,mitochondrial swelling or vacuolization,and a marked decrease in survival rate.There were significant increases in IL-1β,IL-6 and TNF-α levels(P<0.05).Immunofluorescence intensity and protein levels of NeuN,NF200 and MAP2 were notably reduced(P<0.05).Treatment with XXMD improved cell morphology,ultrastructure and survival rate(P<0.05),and decreased in-flammatory factor levels(P<0.05).Compared with model group,the cells in OGD/R+XXMD group showed significantly increased immunofluorescence intensity and protein levels of NeuN,NF200 and MAP2(P<0.05).CONCLUSION:Xiaoxuming decoction may mitigate OGD/R-induced injury,potentially by inhibiting inflammatory responses and enhanc-ing synaptic plasticity.

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.

Pain mechanism in tendinopathy: a review / 中华创伤杂志

Tendons play a crucial role in the motor system. However, tendon injuries can result in pain and function decline, a condition known as tendinopathy. Pain is often the earliest symptom, significantly impacting the lives and work of patients. There are many methods for addressing tendinopathy-associated pain, but the treatment is lengthy and the outcomes are not satisfactory. The main cause is that the mechanism of tendinopathy-associated pain is not completely clear yet. Therefore, it is of great value to identify the mechanism of tendinopathy-associated pain in order to discover new therapeutic strategies. To this end, the authors reviewed the research progress in the mechanisms of tendinopathy-associated pain, including changes in tissue structure, pain mediators, central regulation, etc, to provide a reference for researches on the mechanisms and clinical treatment of tendinopathy-associated pain.

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.

Plasticity of Cultured Neural Networks In Vitro / 生物化学与生物物理进展

Neuronal network is the structural basis for the execution of higher cognitive functions in the brain. Research has shown that learning, memory, and neurodegenerative diseases are closely related to neuronal network plasticity. Therefore, uncovering the mechanisms that regulate and modify neuronal network plasticity is of great significance for understanding information processing in the nervous system and for the treatment of diseases. Currently, neuronal networks cultured on microelectrode array (MEA) provide an ideal model for investigating learning and memory mechanisms in vitro. Additionally, studying such models offers a unique perspective for the prevention and treatment of neurodegenerative diseases. In this review, we summarize relevant research on functional network construction based on recording the electrical signals of neuronal networks cultivated on MEA. We focus on two aspects: 2D neuronal networks and 3D brain organoid development, as well as the effects of open-loop and closed-loop electrical stimulation on neuronal network plasticity. Lastly, we provide an outlook on the future applications of studying neuronal network plasticity using in vitro cultured networks.

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.

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.

Research progress on the parvalbumin-positive inhibitory interneurons and visual developmental plasticity / 眼科新进展

The complex function of the brain depends on the interaction of its intrinsic neurons and neural network systems,in which glutamatergic projection neurons and GABAergic inhibitory interneurons play an important role.There is a critical period in the postnatal development of the visual system when it is susceptible to the external environment,which may affect visual plasticity.Changes in the visual environment can lead to adaptive adjustment in neural connections and synaptic structures among visual cortexes,and the perineural network in the extracellular matrix has been proven to play an essential role in this process.The parvalbumin-positive inhibitory interneurons(PV+INs)contained in the perineural net-works are also involved in regulating plasticity during the critical period of visual development.PV+INs are a kind of inter-neurons that express the parvalbumin found in various parts of the brain.Recent studies have demonstrated that specific modulation of these neurons not only reveals some potential therapeutic mechanisms for disorders such as amblyopia,de-pression and autism but also provides a more precise treatment for these diseases.In this paper,various regulatory factors of PV+INs from their origin to the end of the critical period of visual development and their involvement in visual develop-mental plasticity were reviewed,with the aim of providing some guidance for basic research on visual cortical plasticity.

Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development / 神经科学通报·英文版

The organization of the brain follows a topological hierarchy that changes dynamically during development. However, it remains unknown whether and how cognitive training administered over multiple years during development can modify this hierarchical topology. By measuring the brain and behavior of school children who had carried out abacus-based mental calculation (AMC) training for five years (starting from 7 years to 12 years old) in pre-training and post-training, we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology. We observed the development-induced emergence of the default network, AMC training-promoted shifting, and regional changes in cortical gradients. Moreover, the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy. We found that gradient-based features can predict the math ability within groups. Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.

Neurogenesis and pesticides: news of no new neurons / Neurogênese e pesticidas: a ausência de novos neurônios é a novidade

Abstract New hippocampal neurons are continuously generated in the adult human brain. Several studies have demonstrated that the proliferation of hippocampal cells is strongly influenced by a variety of stimuli, including pesticides exposure. These effects are particularly important because neurogenesis dysregulation could be associated with the decline of neuronal and cognitive functions and the possible development of neuropsychiatric disorders.

Resumo Novos neurônios hipocampais são gerados continuamente no cérebro humano adulto. Vários estudos têm demonstrado que a proliferação de células do hipocampo é influenciada por uma variedade de estímulos, incluindo a exposição a pesticidas. Estes efeitos são particularmente importantes porque a desregulação da neurogênese pode estar associada ao declínio das funções neuronais e cognitivas e ao possível desenvolvimento de doenças neuropsiquiátricas.

Galectins in epithelial-mesenchymal transition: roles and mechanisms contributing to tissue repair, fibrosis and cancer metastasis

Galectins are soluble glycan-binding proteins that interact with a wide range of glycoproteins and glycolipids and modulate a broad spectrum of physiological and pathological processes. The expression and subcellular localization of different galectins vary among tissues and cell types and change during processes of tissue repair, fibrosis and cancer where epithelial cells loss differentiation while acquiring migratory mesenchymal phenotypes. The epithelial-mesenchymal transition (EMT) that occurs in the context of these processes can include modifications of glycosylation patterns of glycolipids and glycoproteins affecting their interactions with galectins. Moreover, overexpression of certain galectins has been involved in the development and different outcomes of EMT. This review focuses on the roles and mechanisms of Galectin-1 (Gal-1), Gal-3, Gal-4, Gal-7 and Gal-8, which have been involved in physiologic and pathogenic EMT contexts.

Investigating the Alkaline Potential of Mineral Trioxide Aggregate Repair Using Selenium Nanoparticles

Resumo Este estudo teve como objetivo determinar o efeito da adição de nanopartículas de selênio (SeNPs) ao agregado de trióxido mineral (MTA HP) em relação ao potencial alcalinizante. Além disso, examinou o material do conjunto após a incorporação de SeNPs usando a microscopia eletrônica de varredura de emissão de campo com análise de raios X por dispersão de energia (FE-SEM/EDX) para caracterizar a composição elementar e as alterações morfológicas resultantes da integração de SeNPs. As amostras de cimento, antes e depois da incorporação de SeNPs, foram examinadas usando FE-SEM/EDX. O nível de pH também foi medido com um pH-metro previamente calibrado com soluções de pH conhecido, para avaliar a atividade alcalinizante da substância integrada em diferentes concentrações de nanopartículas: Grupo 1 (controle): 0% p/p de SeNPs, Grupo 2: 0,5% p/p de SeNPs, Grupo 3: 1% p/p de SeNPs, Grupo 4: 1,5% p/p de SeNPs e Grupo 5: 2% p/p de SeNPs após 1, 7, 14 e 30 dias em água distal. Os dados foram analisados por ANOVA unidirecional e testes de Tukey (P≤0,05). De acordo com o FE-SEM/EDX, as características morfológicas indicam que as SeNPs foram dispersas e integradas com sucesso na matriz de reparo do MTA. A análise de EDX valida a presença de selênio, confirmando a integração bem-sucedida. Os resultados confirmaram que o MTAHP apresentou alto nível de pH com uma redução perceptível na atividade alcalinizante com cada concentração incorporada de (SeNPs) que diferiu significativamente do grupo de controle em vários períodos de tempo (P≤ 0,05). Consequentemente, os resultados indicam que a adição de SeNPs ao MTA HP tem um impacto notável sobre o pH da solução de armazenamento, levando a uma redução significativa nos valores de pH para todas as concentrações e períodos de tempo quando comparados ao grupo de controle. A ação alcalinizante do MTA HP é altamente afetada pelas SeNPs incorporadas, tornando-o mais adequado para aplicação no tecido pulpar. Este estudo contribui para a nossa compreensão das alterações morfológicas e da composição elementar do MTA HP incorporado com SeNPs, aprimorando suas possíveis aplicações na regeneração dentária e tecidual.

Abstract This study aimed to determine the effect of adding selenium nanoparticles (SeNPs) to mineral trioxide aggregate (MTA HP) concerning alkalinizing potential. Additionally, it examined the set material after SeNPs incorporation using Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray analysis (FE-SEM/EDX) for characterizing the elemental composition and morphological alterations resulting from the integration of SeNPs. Cement samples, both before and after SeNPs incorporation, were examined using FE-SEM/EDX. The pH level was also measured with a pH-meter previously calibrated with solutions of known pH, to evaluate the alkalinizing activity of the integrated substance at different concentrations of nanoparticles: Group 1 (control): 0% w/w SeNPs, Group 2: 0.5% w/w SeNPs, Group 3: 1% w/w SeNPs, Group 4: 1.5% w/w SeNPs and Group 5: 2% w/w SeNPs after 1, 7, 14, and 30 days in distal water. The data were analyzed by one-way ANOVA and Tukey tests (P≤0.05). According to FE-SEM/EDX, the morphological characteristics indicate that SeNPs were successfully dispersed and integrated into the MTA repair matrix. EDX examination validates the presence of Selenium, confirming successful integration. The findings confirmed that the MTAHP showed a high pH level with a discernible reduction in the alkalinizing activity with each incorporated concentration of (SeNPs) that significantly differed from the control group across various periods at (P≤ 0.05). Consequently, the findings indicate that the addition of SeNPs to MTA HP has a notable impact on the pH of the storage solution, leading to a significant decrease in pH values for all concentrations and periods when compared to the control group. The alkalinizing action of MTA HP is highly affected by the incorporated SeNPs, making it more suitable for application in pulpal tissue. This study contributes to our understanding of the morphological alterations and elemental composition of SeNP-incorporated MTA HP, enhancing its potential applications in dental and tissue regeneration.