Acteoside Attenuates Recognition Memory Impairment in CUMS Rats via Regulating Synaptic Plasticity and mTOR Signaling Pathway

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.

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 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.

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.

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.

The P300 Auditory Evoked Potential in Cochlear Implant Users: A Scoping Review

Abstract Introduction The P300 auditory evoked potential is a long-latency cortical potential evoked with auditory stimulation, which provides information on neural mechanisms underlying the central auditory processing. Objectives To identify and gather scientific evidence regarding the P300 in adult cochlear implant (CI) users. Data Synthesis A total of 87 articles, 20 of which were selected for this study, were identified and exported to the Rayyan search software. Those 20 articles did not propose a homogeneous methodology, which made comparison more difficult. Most articles (60%) in this review compare CI users with typical hearing people, showing prolonged P300 latency in CI users. Among the studies, 35% show that CI users present a smaller P300 amplitude. Another variable is the influence of the kind of stimulus used to elicit P300, which was prolonged in 30% of the studies that used pure tone stimuli, 10% of the studies that used pure tone and speech stimuli, and 60% of the studies that used speech stimuli. Conclusion This review has contributed with evidence that shows the importance of applying a controlled P300 protocol to diagnose and monitor CI users. Regardless of the stimuli used to elicit P300, we noticed a pattern in the increase in latency and decrease in amplitude in CI users. The user's experience with the CI speech processor over time and the speech test results seem to be related to the P300 latency and amplitude measurements.

Perfil Neurocognitivo de una cohorte de menores de edad con vivencias de maltrato infantil / Neuropsychological profile of a cohort of children victims of child abuse

El maltrato infantil (MI) es un problema multidimensional. El estrés crónico producido por dicho fenómeno afecta el desarrollo cerebral de niños, niñas y adolescentes (NNA), incidiendo negativamente en la evolución de diversos aspectos del desarrollo, condicionando su vida futura. El objetivo de este estudio es analizar el desempeño sociocognitivo de NNA que han vivenciado MI, mediante el análisis de las funciones del neurodesarrollo, evaluado con subpruebas de la NEPSY II. Se analizan funciones ejecutivas y percepción social, bases del razonamiento y adaptación social. Se estudia el desempeño de 14 de NNA pertenecientes a un Programa de la Fundación Súmate, cuya Misión es la recuperación de la escolaridad NNA que han visto alterado el curso de su desarrollo por MI. Los resultados dan cuenta de alteraciones cerebrales asociadas al MI, las que se evidencian en un deficitario desarrollo funcional de las variables estudiadas. Existe grave descenso en los procesos y subprocesos del funcionamiento ejecutivo. En relación con la percepción social, la muestra estudiada presenta un mejor desarrollo, el que desciende a medida que aumenta la edad. Las funciones estudiadas tienen directa relación con el razonamiento cognitivo y desarrollo socio adaptativo, bases sobre las que se estructura el desarrollo académico. Los hallazgos, refuerzan la urgencia de abordar esta sensible realidad desde la práctica médica en la atención primaria y especializada. Los resultados también son de utilidad para orientar el desarrollo de políticas públicas que efectivamente contribuyan al progreso de nuestro país.

Abstract. Child maltreatment (MI) is a multidimensional problem. The chronic stress produced by this phenomenon affects the brain development of children and adolescents (NNA), negatively affecting the evolution of various aspects of development, conditioning their future life. The objective of this study is to analyze the sociocognitive performance of children and adolescents who have experienced IM, through the analysis of the performance of neurodevelopmental functions, evaluated through subtests of the NEPSY II. Executive functions and social perception, reasoning bases and social adaptation are studied. The performance of 14 NNA belonging to a Fundación Súmate Program is studied, whose mission is the recovery of NNA schooling that has seen the course of their development altered by IM. The results show brain alterations associated with MI, evidenced in a deficient functional development of the variables studied. There is a serious decline in the processes and threads of executive functioning. In relation to social perception, the studied sample presents a better development, which decreases as age increases. The functions studied are directly related to cognitive reasoning and socio-adaptive development, based on which academic development is structured. The findings reinforce the urgency of addressing this sensitive reality from medical practice in primary and specialized care. The results are also useful to guide the development of public policies that effectively contribute to the progress of our country.

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.

"Shapeshifter of the mycobacterial world" : Discuss the mechanism of morphological transformation of Mycobacterium abscesses / 中华临床感染病杂志

Mycobacterium abscessesus (MAB) is the most common species of rapidly growing pathogenic nontuberculous mycobacteria (NTM). MAB is also an opportunistic pathogen with high drug resistance. The unique structure of cell wall enables it to exist in different forms and to undergo morphological transformation, making it the "shapeshifter of the mycobacterial world" , which facilitates its survival in natural environment in a saprophytic manner; and also facilitates its invasion into the host with long-term survival and being pathogenic. This article reviews research progress on the specific deformability of MAB and the mechanism associated with its phenotypic transformation; discusses the evolutionary characteristics of MAB to adapt environmental changes to provide reference for better understanding the biological characteristics and pathogenicity of MAB.

Effect of acute sleep fragmentation on cognitive function and hippocampal Homer1a expression in aged rats / 中华行为医学与脑科学杂志

Objective:To explore the effects of acute sleep fragmentation (SF) on cognitive function and the relationship between hippocampal Homer1a and synaptic plasticity in aged rats.Methods:One hundred and eight SPF grade male SD rats aged 22 to 24 months were divided into three groups according to random number table: control group (Control group), non-sleep fragmentation group (NSF group) and sleep fragmentation group (SF group), with 36 rats in each group.A sleep fragmentation model was established by sleep deprivation rod method.Morris water maze and novel object recognition tests were used to evaluate the learning and memory function of rats.Homer1a expression in hippocampus was detected by Western blot, and its distribution in CA1 area of hippocampus was observed by immunohistochemical staining.Golgi staining was used to observe the density of dendritic spines in CA1 area of hippocampus, and in vitro electrophysiological patch clamp test was used to detect the slope of field excitatory postsynaptic potential(fEPSP) from CA3 to CA1 in hippocampus.SPSS 22.0 and GraphPad Prism 9.3 softwares were used for data statistical analysis and mapping.One-way ANOVA was used for comparison among groups, and Tukey-Kramer test was used for further pairwise comparison. Results:(1)In the behavioral tests, there were statistical differences in the times of crossing the original platform, the target quadrant residence time and the new object recognition index at 1 h and 24 h among the three groups( F=13.63, 11.34, 21.26, 16.22, all P<0.01). The times of crossing the original platform in SF group((2.00±1.27) times) was lower than that of Control group ((5.67±2.16) times) and NSF group ((6.50±2.35) times) (both P<0.05). The target quadrant residence time in SF group ((9.02±4.84) s) was shorter than that in Control group ((24.73±7.37) s) and NSF group ((27.81±8.37)s) (both P<0.05). The new object recognition index at 1 h and 24 h in SF group were lower than those in Control group and NSF group (all P<0.05). (2) In Western blot assay, the expression of Homer1a protein in hippocampus of SF group(0.91±0.13) was higher than that of Control group(0.70±0.05) and NSF group(0.74±0.04)(both P<0.05). (3) In immunohistochemical staining, the optical density value of the Homer1a protein in CA1 area of hippocampus in the SF group was higher than that in the Control group and NSF group(both P<0.05). (4) In Golgi staining, the density of dendritic spines in CA1 area of hippocampus in SF group was lower than that in Control group and NSF group (both P<0.05). (5) In vitro electrophysiological test showed that the slope of fEPSP in CA3-CA1 area of hippocampus in SF group were lower than that in Control group and NSF group (both P<0.05). Conclusion:Acute SF intervention in aged rats can cause cognitive impairment, which may be associated with the inhibition of hippocampal synaptic plasticity induced by hippocampal Homer1a overexpression.

Synaptic plasticity after ischemic brain injury / 国际脑血管病杂志

Ischemic stroke is a common disease of the nervous system, which is characterized by high incidence, recurrence, disability and mortality rate. The pathological mechanism of ischemic brain injury is complex. Synaptic plasticity injury is considered to be the earliest pathological change after cerebral ischemia, and regulating synaptic plasticity is one of the important mechanisms to promote the recovery of neurological function after stroke. This article reviews the advances in synaptic plasticity after ischemic brain injury, which provides theoretical basis for the development of neuroprotective drugs in the future.

Progress on the role of the RARα regulating homeostatic synaptic plasticity in the pathogenesis of autism spectrum disorders / 国际儿科学杂志

Autism spectrum disorders(ASD)is an important disease in children′s neuropsychic development disorder.The incidence rate is increasing now, which brings heavy burden to family and society.Functional studies of ASD related different single gene mutation models have showed that these overlapping phenotypes shared the common mechanism of the homeostatic synaptic plasticity impairment.Retinoic acid receptor α(RARα)regulate synaptic plasticity of the nervous system in both directions, through glutamate receptor subunit 1(GluR1)translation and RARα/mTOR signaling pathway, and affect the integration of sensory information and situational adaptive learning, and then affect the learning and memory function and neural synaptic signal network through the growth of dendritic spines.These researches suggest that RARα may work as a potential drug target for ASD, playing an important role in stable regulation of homeostatic synaptic plasticity, which is helpful for molecular typing accurate diagnosis and treatment of ASD.

Dihydroartemisinin Regulates Neuro-microglia to Relieve Neuropathic Pain / 中国实验方剂学杂志

ObjectiveTo evaluate the intervention effect of dihydroartemisinin （DHA） on hippocampal nerve injury in L5 spinal nerve ligation （SNL） model and tumor necrosis factor-α （TNF-α） hippocampal continuous injection model. In primary cultured microglia-hippocampal neurons， the regulatory pattern of DHA on microglia-hippocampal neuronal interactions was confirmed. MethodThe experimental animals were divided into Sham group， SNL group， and DHA group （16 mg·kg-1）， with 3 mice in each group. The hippocampal CA3 glutamatergic neurons were labeled with adeno-associated virus ［Calmodulin-dependent protein kinase Ⅱ（CaMKⅡ） dTomato AAV］， and their contributions to the hippocampal CA1， prefrontal cortex （Frc）， anterior cortex （ACC）， projections of nucleus accumbens （Nac）， and Basolateral Amygdala （BLA） were traced by immunofluorescence staining. The experimental animals were divided into a Sham group， a TNF-α hippocampus continuous injection model group， DHA-L， DHA-M， and DHA-H groups （4， 8， 16 mg·kg-1）， and pregabalin group （25 mg·kg-1）， with 4 mice in each group. The morphology of pyramidal neurons in the hippocampal CA1 and CA3 regions was counted by Golgi staining. The continuous activation of hippocampal primary neurons and microglia was induced， DHA intervention was given by co-culture， and the cell soma area and the expression of postsynaptic density protein 95 （PSD95） inside and outside the primary and secondary dendritic spines of neurons were counted by immunofluorescence. ResultCompared with the Sham group， the projection of CA3 glutamatergic neurons to CA1 region， Frc， and ACC in the SNL group was significantly reduced （P<0.01）， while the projection to Nac and BLA was significantly increased （P<0.01）. As compared with the SNL group， the projection of hippocampal CA3 glutamatergic neurons to CA1 region， Frc， and ACC was significantly increased in the DHA group （P<0.01）， while the projection to Nac and BLA was significantly reduced （P<0.01）. Golgi staining results showed that as compared with the Sham group， the density of dendritic spines and the number of dendritic branches in the CA1 and CA3 pyramidal neurons in the TNF-α hippocampal continuous injection model group were significantly reduced （P<0.01）. As compared with the TNF-α hippocampal continuous injection model， the density of dendritic spines and the number of dendritic branches in hippocampal CA1 and CA3 pyramidal neurons in the DHA-M and DHA-H groups were significantly increased （P<0.05， P<0.01）. Compared with DHA-M group， the total dendrite length of CA1 pyramidal neurons in hippocampus in DHA-H group was significantly increased （P<0.01）， while the total dendrite length of CA1 neurons and the total dendrite base length of CA3 neurons in DHA-L group was significantly decreased （P<0.01）. Compared with the blank control group， the cell soma area of the glycine group and glutamate group increased significantly （P<0.01）. As compared with the glycine group and glutamate group， the cell area of the glycine + glutamate group was significantly increased （P<0.01）， and as compared with the glutamate group， the cell soma area of the glutamate + DHA group was significantly reduced （P<0.01）. As compared with the glycine acid + glutamate group， the cell soma area of the glycine + glutamate + DHA group was significantly reduced （P<0.01）， and as compared with the glutamate + DHA group， the cell soma area of the glycine + glutamate + DHA group was also significantly reduced （P<0.05）. Compared with the blank control group， the cell soma area of the glutamate group was significantly increased （P<0.01）. As compared with the glutamate group， the cell soma area of the glutamate + DHA-L， glutamate + DHA-M， and glutamate + DHA-H groups was significantly reduced （P<0.01）. As compared with the blank control group， the expression of the resting primary microglia + glycine group in primary and secondary dendritic internal and external postsynaptic density protein 95 （PSD95） was significantly increased （P<0.01）. As compared with the resting primary microglia + glycine group， the expression of PSD95 in the primary and secondary dendritic spinous and external neurons of the activated primary microglia + glycine group was significantly reduced （P<0.01）. As compared with the activated primary microglia + glycine group， the expression of PSD95 in the primary and secondary dendritic spinous and external neurons in the activated primary microglia + glycine + DHA group was significantly increased （P<0.01）. As compared with the activated primary microglia + DHA group， the expression of PSD95 in the primary and secondary dendritic spines and outside neurons in the activated primary microglia + glycine + DHA group was significantly increased （P<0.01）. ConclusionDHA has a significant repair effect on vertebral neuronal damage caused by hippocampal microglia and TNF-α overexpression in NP pathology， and this repair is closely related to the dual inhibition of neuronal-microglia by DHA.

The Memory Orchestra: Contribution of Astrocytes / 神经科学通报·英文版

For decades, memory research has centered on the role of neurons, which do not function in isolation. However, astrocytes play important roles in regulating neuronal recruitment and function at the local and network levels, forming the basis for information processing as well as memory formation and storage. In this review, we discuss the role of astrocytes in memory functions and their cellular underpinnings at multiple time points. We summarize important breakthroughs and controversies in the field as well as potential avenues to further illuminate the role of astrocytes in memory processes.

Contextual Fear Learning and Extinction in the Primary Visual Cortex of Mice / 神经科学通报·英文版

Fear memory contextualization is critical for selecting adaptive behavior to survive. Contextual fear conditioning (CFC) is a classical model for elucidating related underlying neuronal circuits. The primary visual cortex (V1) is the primary cortical region for contextual visual inputs, but its role in CFC is poorly understood. Here, our experiments demonstrated that bilateral inactivation of V1 in mice impaired CFC retrieval, and both CFC learning and extinction increased the turnover rate of axonal boutons in V1. The frequency of neuronal Ca2+ activity decreased after CFC learning, while CFC extinction reversed the decrease and raised it to the naïve level. Contrary to control mice, the frequency of neuronal Ca2+ activity increased after CFC learning in microglia-depleted mice and was maintained after CFC extinction, indicating that microglial depletion alters CFC learning and the frequency response pattern of extinction-induced Ca2+ activity. These findings reveal a critical role of microglia in neocortical information processing in V1, and suggest potential approaches for cellular-based manipulation of acquired fear memory.

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.

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.

A bio-inspired hierarchical spiking neural network with biological synaptic plasticity for event camera object recognition / 生物医学工程学杂志

With inherent sparse spike-based coding and asynchronous event-driven computation, spiking neural network (SNN) is naturally suitable for processing event stream data of event cameras. In order to improve the feature extraction and classification performance of bio-inspired hierarchical SNNs, in this paper an event camera object recognition system based on biological synaptic plasticity is proposed. In our system input event streams were firstly segmented adaptively using spiking neuron potential to improve computational efficiency of the system. Multi-layer feature learning and classification are implemented by our bio-inspired hierarchical SNN with synaptic plasticity. After Gabor filter-based event-driven convolution layer which extracted primary visual features of event streams, we used a feature learning layer with unsupervised spiking timing dependent plasticity (STDP) rule to help the network extract frequent salient features, and a feature learning layer with reward-modulated STDP rule to help the network learn diagnostic features. The classification accuracies of the network proposed in this paper on the four benchmark event stream datasets were better than the existing bio-inspired hierarchical SNNs. Moreover, our method showed good classification ability for short event stream input data, and was robust to input event stream noise. The results show that our method can improve the feature extraction and classification performance of this kind of SNNs for event camera object recognition.

Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats / 中国中药杂志

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

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.