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.

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.

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.

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.

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.

Effects of long-term alcohol consumption on synaptic plasticity of mossy fiber-granule cells in cerebellar cortex and motor coordination function in mice / 中华行为医学与脑科学杂志

Objective:To investigate the long-term alcohol consumption on synaptic plasticity of mossy fiber-granule cells in cerebellar cortex and motor coordination function in mice.Methods:Thirty healthy male ICR mice aged 6-8 weeks were divided into saline group (control group)and alcohol consumption group(alcohol group) according to random number table with 15 in each group. The mice in alcohol group were injected intraperitoneally with 15% ethanol (1.6 g/kg), while the mice in control group were injected with the same volum of normal saline, all mice were injected intraperitoneally once a day for 28 consecutive days. Walking obstacle test and rotating rod fatigue test were used to observe the motor coordination ability and learning ability of mice. Electrophysiological patch clamp technique was used to detect the field potential changes of long-term synaptic plasticity induced by blowing stimulation. SPSS 22.0 software was used for statistical analysis.Independent sample t-test, paired t-test and repeated measurement analysis of variance were used for comparison between the two groups before and after intervention. Results:The electrophysiological results showed that the amplitude percentage of field potential N1 wave in the control group after blowing stimulation was (130.4±3.3)%, which was higher than that before stimulation ((100.6±2.7)%) ( t=27.07, P<0.01). And the percentage of area under N1 standardized waveform after stimulation ((128.8±4.5)%) was greater than that before stimulation ((100.2±3.5)%) ( t=19.43, P<0.01). There was no significant difference in the amplitude percentage of N1 wave in alcohol group ((97.8±4.3)%) after blowing stimulation compared with that before stimulation ((99.5±5.6)%) ( t=0.93, P>0.05). And also there was no significant difference in the area percentage under N1 wave after stimulation ((96.8±3.6)%) compared with that before stimulation ((100.2±4.2)%) ( t=2.38, P>0.05). The results of walking obstacle test showed that the total number of errors (3.14±0.19) in the alcohol group was higher than that in the control group(1.52±0.29) ( t=17.87, P<0.01), and the total error time ((63.85±9.34) ms) was longer than that in the control group ((28.93±7.21) ms) ( t=11.45, P<0.01). The results of repeated measurement analysis of variance showed that there was an interaction between time and group in the falling speed and falling latency of the two groups of mice in the rotating rod fatigue experiment ( F=4.5, 455.1, both P<0.05). The drop speed of mice in the alcohol group was significantly lower than that in the control group from day 1 to 7 (all P<0.05). The fall latency of mice in the alcohol group from day 1 to 7 was shorter than that in the control group, and the difference was statistically significant (all P<0.05). Conclusion:Long-term alcohol consumption impairs synaptic plasticity in the granular layer of mice and leads to a significant decline in motor coordination and motor learning ability.

Effects of early sleep deprivation on depressive-like behavior and hippocampus synaptic plasticity in adult depression model mice / 中华行为医学与脑科学杂志

Objective:To investigate the effects of early sleep deprivation(SD) on depressive-like behavior and hippocampus synaptic plasticity in adult mice with chronic unpredictable mild stress(CUMS) model.Methods:Thirty 2-week-old clean grade male mice were randomly divided into control group (CON group), CUMS group and SD + CUMS group according to the random number table, with 10 mice in each group. The mice in SD + CUMS group were subjected with sleep deprivation for 4 hours once a day during puberty (3 ~ 6 weeks old), and then were stimulated by CUMS after adulthood (9 weeks old). The mice in CUMS group were subjected with CUMS at the age of 9 weeks. And the mice in CON group were not given any intervention.The depressive-like behavior was evaluated by body weight, sugar water preference, tail suspension test and forced swimming test.The density of dendritic spines of basal and apical neurons in hippocampal CA1 was measured by Golgi staining, the frequency and amplitude of miniature excitatory postsynaptic current(mEPSC) of pyramidal neurons in the hippocampal CA1 region of mice were measured by electro-physiological patch clamp technique.Graphpad prism 7.0 software was used for statistical analysis and mapping. One-way ANOVA was used for comparison among multiple groups, and Tukey test was used for further pairwise comparison.Results:(1) After stress modeling, there were significant differences in body weight, sugar water preference percentage, forced swimming immobility time and tail suspension time among the three groups ( F=71.63, 39.82, 44.13, 43.07, all P<0.01). Compared with CON group, the mice in CUMS group and SD+ CUMS group had lower body weight ((25.51±0.37) g, (22.92±0.31) g, (20.12±0.27) g, both P<0.01), lower sugar water percentage preference ((87.40±1.65) %, (63.42±3.33) %, (49.68±3.70)%, both P<0.01), longer immobile time of forced swimming ((34.30±5.32) s, (119.20±12.03) s, (153.80±9.17) s, both P<0.01) and longer immobile time of tail suspension test((115.20±8.19)s, (156.80±4.35) s, (192.00±4.12) s, both P<0.01). Compared with CUMS group, SD+ CUMS group had lower body weight ( P<0.01), lower sugar water preference percentage ( P<0.05), longer immobile time in forced swimming test( P<0.05) and longer immobile time in tail suspension test( P<0.01). (2) Golgi staining results showed that the densities of dendritic spines of apical neurons and basal neurons in hippocampal CA1 area of the three groups were significantly different ( F=38.41, 41.34, both P<0.01). The densities of dendritic spines of basal and apical hippocampal neurons in CUMS group and SD+ CUMS group were lower than those in CON group ((7.74±0.22)/10 μm, (6.58±0.27)/10 μm, (5.00±0.13)/10 μm, both P<0.01), ((8.90±0.23)/10 μm, (7.63±0.30)/10 μm, (6.01±0.14)/10 μm, both P<0.01). Compared with CUMS group, the mice in SD+ CUMS group had lower densities of dendritic spines of basal and apical hippocampal neurons(both P<0.01). (3) Electrophysiological results showed that there were significant differences in the frequency and amplitude of mEPSC in hippocampal pyramidal neurons of the three groups ( F=38.90, 63.37, both P<0.01). Compared with CON group, the frequency and amplitude of mEPSC in pyramidal neurons of CA1 in CUMS group and SD+ CUMS group were significantly lower ((0.39±0.03)Hz, (0.20±0.02)Hz, (0.07±0.02)Hz, both P<0.01; (9.98±0.31)pA, (7.74±0.21)pA, 6.36±0.13)pA, both P<0.01). Compared with CUMS group, the frequency and amplitude of mEPSC in SD+ CUMS group were lower (both P<0.01). Conclusion:Adolescent sleep deprivation aggravates depressive behavior and hippocampus synaptic plasticity impairment in adult CUMS model mice.

Role of Shh/Gli1 signaling pathway in sleep deprivation-induced cognitive impairment in young mice / 中华麻醉学杂志

Objective:To evaluate the role of sonic hedgehog (Shh)/glioma-associated oncogene homolog 1 (Gli1) signaling pathway in sleep deprivation-induced cognitive impairment in young mice.Methods:Forty-eight SPF healthy male C57BL/6 mice, aged 4 weeks, weighing 14-16 g, were divided into 3 groups ( n=16 each) by the random number table method: control group (C group), sleep deprivation group (SD group) and Shh agonist SAG group (SD+ SAG group). Multi-platform water environment method was used to prepare the sleep deprivation model in mice, and the sleep deprivation was 20 h a day for 10 consecutive days.In SD+ SAG group, SAG 10 mg/kg was intraperitoneally injected at 5 min before each sleep deprivation, while the equal volume of normal saline was intraperitoneally injected in group C and group SD.The mice underwent novel object recognition and Y-maze tests at 24 h after development of the model.Mice were sacrificed after the behavioral testing, and the hippocampi were isolated for determination of the density of dendritic spines in hippocampal CA1 region (by Golgi staining), expression of Gli1 and brain-derived neurotrophic factor (BDNF) in hippocampal tissues (by Western blot), and expression of Gli1 and BDNF mRNA in hippocampal tissues (by quantitative real-time polymerase chain reaction). Results:Compared with group C, the preference index in novel object recognition and Y-maze tests and density of dendritic spines in CA1 region were significantly decreased, and the expression of Gli1 and BDNF protein and mRNA in hippocampus was down-regulated in group SD ( P<0.05). Compared with group SD, the preference index in novel object recognition and Y-maze tests and density of dendritic spines in CA1 region were significantly increased, and the expression of Gli1 and BDNF protein and mRNA in hippocampus was up-regulated in group SD+ SAG ( P<0.05). Conclusions:Inhibition of Shh/Gli1 signaling pathway and reduction of plasticity of dendritic spines of hippocampal neurons are involved in sleep deprivation-induced cognitive impairment in young mice.

Research progress of chronic ethanol consumption on neural circuits of cerebellum and behaviors / 中华行为医学与脑科学杂志

Ethanol is one of the most widely used and abused psychoactive substances in the world. Long-term and excessive intake of alcohol can damage the central nervous system and lead to impairment of its function. As an important component of the central nervous system, cerebellum is one of the main target organs damaged by ethanol. Acute and chronic ethanol intake can damage human motor coordination, motor learning and some cognitive functions. Its damage mechanism is generally believed to be caused by the abnormal function of cerebellar cortical neural circuit caused by ethanol intake. Combined with recent studies on the mouse model of long-term ethanol intake, this article reviews the cerebellar neural network mechanism of long-term ethanol intake from various aspects, with a view to providing research and development in behavioral movement, motor coordination, cognitive function, depression, and offers new ideas with the rise of precision medicine for treatment. People are increasingly interested in exploring the mechanism of long-term ethanol intake on the cerebellar neural network. How to improve or block the corresponding mechanism based on the mechanism of action found in existing research is an important proposition in future research.

Effects of ganoderma triterpenoids combined with exogenous GM1 on cognitive function and hippocampal synaptic structure in rats with epilepsy / 中华行为医学与脑科学杂志

Objective:To study the intervention effect of ganoderma triterpenoids combined with exogenous monosialotetrahexosyl ganglioside(GM1) on cognitive dysfunction and synaptic ultrastructure of hippocampal neurons in rats with epilepsy caused by pentylenetetrazol(PTZ).Methods:A total of 40 Sprague-Dawley rats were divided into blank control group, epileptic model group, ganoderma triterpenoids group, GM1 group and GM1 combined with ganoderma triterpenoids group according to the random number table method( n=8 in each group). The rats were intraperitoneally injected with PTZ subconvulsant dose (35 mg·kg -1·d -1) once a day for 28 days to replicate the models of chronic epilepsy. And the rats in different medication groups were given corresponding administration based on daily intraperitoneal injection of PTZ(GM1: intraperitoneal injection of 30 mg·kg -1·d -1, ganoderma triterpenoids: gavage 1 000 mg·kg -1·d -1). Morris water maze was used to test the spatial exploration and learning and memory ability of epileptic rats.Transmission electron microscopy was used to observe the ultrastructure of hippocampal neurons in epileptic rats.Immunofluorescence staining was used to observe expression levels of cofilin and SYN protein in hippocampus CA1 of rats. In addition, Western blot was used to detect the expression levels of cofilin, p-cofilin and synaptophysin(SYN) protein in hippocampus of rats. SPSS 17.0 software was used for statistical analysis. Repeated one-way ANOVA was used for comparing among groups, LSD test was used for pairwise comparisons. Results:Morris water maze results showed that there were statistically significant differences in escape latency, times of crossing the platform and time spent in the target quadrant among the groups( F=5.259, 8.240, 5.961, all P<0.05). Compared with the epilepsy model group, the escape latencies((20.31±7.39) s, (21.81±6.05) s, (17.66±4.76) s) of the ganoderma triterpenoids group, GM1 group and GM1 combined with ganoderma triterpenoids group were shorter (all P<0.05), the numbers of crossing the platform ((4.63±1.41) times, (4.50±1.93) times, (5.50±1.77) times) were more (all P<0.05), the residence time in target quadrant ((31.91±5.00) s, (30.49±5.72) s, (35.70±5.34) s) were longer (all P<0.05). And the most obvious change was found in the GM1 combined with ganoderma triterpenoids group ( P<0.01). The results of transmission electron microscope showed that there were significant differences in the numbers of hippocampal neurons synapses, the synaptic gap, the density of postsynaptic membrane and length of active area of postsynaptic membrane among the groups( F=3.693, 7.201, 5.012, 4.033, all P<0.05). Compared with the epilepsy model group, the numbers of synapses ((8.00±1.79), (7.83±1.84), (8.50±1.87)) in the ganoderma triterpenoids group, GM1 group and GM1 combined with ganoderma triterpenoids group were all more (all P<0.05), synaptic gap ((33.83±3.81)nm, (32.43±4.14)nm, (30.23±3.08)nm)were narrower, and the postsynaptic dense substances ((57.50±6.03)nm, (58.10±2.40)nm, (60.73±3.81)nm) were all thicker (all P<0.05). The length of active region of postsynaptic membrane ((271.66±11.80) nm, (279.06±13.58) nm) in ganoderma triterpenoid group and GM1 combined with ganoderma triterpenoids group were longer than that in epilepsy model group (both P<0.05). Immunofluorescence results showed that the average fluorescence intensity of cofilin in the epilepsy model group was higher than that in the blank control group, and the average fluorescence intensity of SYN was lower than that in the blank control group (both P<0.05). The average fluorescence intensity of cofilin in GM1 group and GM1 combined with ganoderma triterpenoids group were lower than that in epilepsy model group (both P<0.05), and the average fluorescence intensity of SYN in ganoderma lucidum triterpenoids combined with GM1 group was higher than that in epilepsy model group ( P<0.05). Western blot showed that the expression levels of cofilin protein in the epilepsy model group was higher than that in the blank control group ((1.454±0.080), (1.092±0.099), P<0.05), and the expression of p-cofilin and SYN were lower than those in the blank control group ((1.103±0.120) vs (1.420±0.934), (1.650±0.062) vs (1.958±0.062), both P<0.05). The expression of cofilin protein ((1.227±0.071), (1.262±0.078), (1.162±0.129), P<0.05) in ganoderma triterpenoids group, GM1 group and GM1 combined with ganoderma triterpenoids group were lower than that in epilepsy model group, and the expression levels of p-cofilin(1.357±0.199) and SYN protein(1.873±0.010) in ganoderma triterpenoids combined with GM1 group were higher than that in epilepsy model group (both P<0.05). Compared with ganoderma lucidum triterpenoids group and GM1 group, there was no significant difference in each index of GM1 combined with ganoderma triterpenoids group (all P>0.05). Conclusion:GM1 combined with ganoderma triterpenoids may promote the synaptic plasticity of neurons, improve the learning and memory ability of epileptic rats.Combination medication is better than single medication in some observed indicators.

Role and mechanisms of synaptic plasticity decrease mediated by KIBRA in cognitive dysfunction by chronic cerebral hypoperfusion / 中华行为医学与脑科学杂志

Objective:To explore the role and mechanism of kidney brain protein (KIBRA) down-regulation in cognitive dysfunction caused by chronic cerebral hypoperfusion.Methods:Ninety male SPF grade Sprague Dawley (SD) rats were divided into four groups according to random number table: sham operation group ( n=15), chronic hypoperfusion group (2VO group, n=25), chronic hypoperfusion stereotaxic injection of AAV-KIBRA group (2VO+ AAV-KIBRA group, n=25), chronic hypoperfusion stereotaxic injection of AAV-Vector group (2VO+ AAV-vector group, n=25). Chronic cerebral hypoperfusion model was established by bilateral ligation of common carotid artery, and stereotactic injection of 2 μL AAV-KIBRA or AAV-vector was performed for 30 days.Morris water maze, in vitro electrophysiology, p21-activated kinase 3(PAK3) activity detection, Western blot, immunoprecipitation and Golgi staining were used to detect spatial learning and memory ability, long-term potentiation(LTP), KIBRA level expression, PAK3 activity changes and the distribution of dendritic spines.SPSS 16.0 statistical software was used for statistical data.One-way ANOVA was used to compare the differences between groups.LSD test was used to compare the significance of data differences between the two groups.Welch test was used for uneven variance. Results:After 1 month of chronic cerebral hypoperfusion, the level of KIBRA in the hippocampus of rats was detected by homogenate and Western blot, and it was found that the level of KIBRA in 2VO group was lower than that of sham group(73.49±4.12)% ( P<0.01). AAV-KIBRA injection in hippocampal CA1 region significantly up-regulated the level of KIBRA to (91.91±7.01)% over 2VO group ( P<0.01). Morris water maze test showed that the latency of the 2VO group(3rd-7th day trail data: (48.18±2.82)s, (43.45±2.27)s, (32.27±2.22)s, (26.55±2.37)s, (17.18±2.67)s) were significantly longer than those of the sham group((41.67±2.74)s, (32.58±2.57)s, (22.50±2.94)s, (16.91±2.39)s, (8.75±1.52)s) (all P<0.05), and the latencies of the 2VO+ AAV-KIBRA group 3rd-7th day trail data: (43.83±2.95)s, (35.25±2.15)s, (26.58±2.03)s, (19.92±2.17)s, (17.75±1.35)s) was significantly shorter than that of the 2VO group ((all P<0.01). The Morris water maze test with the platform removed showed that the latency of rats in the 2VO group to reach the platform region was significantly longer than that of the sham group, while the latency of rats in the 2VO+ AAV-KIBRA group to reach the platform region was significantly shorter than that in the 2VO group ( P<0.01). At the same time, the retention time and the crossing times in the platform region of 2VO group were less than those of the sham group ( P<0.01), but the retention time and the crossing times in the platform region of 2VO+ AAV-KIBRA group were significantly higher than those in the 2VO group ( P<0.01). The electrophysiological records of the brain slices showed that the relative excitatory postsynaptic field potential of 2VO group (1.43±7.43) was significantly lower than that of sham group (2.21±6.54) after high frequency stimulation, while the relative excitatory postsynaptic field potential of 2VO+ AAV-KIBRA group (1.90±8.15) was higher than that of 2VO group ( P<0.01). Immunoprecipitation in rat hippocampus revealed that PAK3 could be detected by Western blot assay when KIBRA was precipitated.The results showed that the relative enzyme activity of PAK3 in 2VO hippocampal tissue (0.64±0.04) was significantly lower than that in sham group (1.02±0.07), while the relative enzyme activity of PAK3 in 2VO+ AAV-KIBRA group (0.86±0.03) was significantly higher than that in 2VO group.Golgi staining showed that the density of dendritic spines in 2VO hippocampal neurons((6.85±0.43)/10 μm) was significantly lower than that in sham group((11.83±0.58)/10 μm), while the density of dendritic spines in 2VO+ AAV-KIBRA group((10.22±0.39)/10 μm) was significantly higher than that in 2VO group. Conclusion:The down-regulated of KIBRA after chronic cerebral hypoperfusion plays a key role in cognitive dysfunction and is also involved in the decrease of synaptic functional plasticity.The downregulation of KIBRA is involved in the structural plasticity of dendrites through the regulation of PAK3 activity.Therefore, KIBRA may be an important target for the prevention and treatment of cognitive function of chronic cerebral hypoperfusion.

Effect of Suanzaoren Tang on Learning， Memory and Expression of Proteins Related to Hippocampal Synaptic Plasticity in PCPA-induced Insomnia Rat Model / 中国实验方剂学杂志

ObjectiveTo observe the effects of Suanzaoren Tang on the behavior， growth-associated protein-43 （GAP-43）， postsynaptic density protein-95 （PSD-95）， and synaptophysin Ⅰ （SynⅠ） of insomniac rats induced by p-chlorophenylalanine （PCPA）， and to investigate the mechanism of Suanzaoren Tang in improving the behavior of the insomniac rats. MethodSeventy-two SD rats were randomly assigned into 6 groups （12 rats in each group）： control group （normal saline）， PCPA （0.35 g·kg-1·d-1） group， estazolam （2.7×10-4 g·kg-1·d-1） group， and low-， medium-， and high-dose （3.25， 7.5， 15 g·kg-1·d-1， respectively） Suanzaoren Tang groups. The rat model of insomnia was established by intraperitoneal injection of PCPA and then the rats were administrated with corresponding drugs for 7 continuous days. The Morris water maze and Y-maze were used to test the learning and memory functions， and the open field to test anxiety. Histopathological changes in the hippocampus were observed via hematoxylin-eosin （HE） staining. The mRNA and protein levels of GAP-43， PSD-95， and SynⅠ in hippocampus were determined by real-time fluorescence quantitative polymerase chain reaction (Real-time PCR)， Western blot， and immunohistochemistry （IHC）. ResultCompared with the control group， the PCPA group showcased long escape latency， shortened time in the quadrants， and decreased times of crossing the platform in Morris water maze， decreased alternation correct rate was significantly Y-maze， and increased distance， mean velocity， and time in center of the open field test （P<0.01）. Furthermore， the PCPA-treated rats showed obvious pathological damage in the hippocampus and down-regulated mRNA and protein levels of GAP-43， PSD-95， and SynⅠ in hippocampus （P<0.01）. Compared with the PCPA group， the treatments with estazolam and different doses of Suanzaoren Tang improved the rat performance in Morris water maze， Y-maze， and open field test （P<0.05， P<0.01）， alleviated the hippocampal damage， and up-regulated the mRNA and protein levels of GAP-43， PSD-95， and SynⅠ （P<0.05， P<0.01）. ConclusionSuanzaoren Tang may alleviate the learning and memory disorders and anxiety in PCPA-induced insomnia rat model by up-regulating the mRNA and protein levels of hippocampal synaptic plasticity-associated proteins GAP-43， PSD-95， and SynⅠ.

Mechanism of Kaixinsan on Learning and Memory Ability and Synaptic Function of APP/PS1 Mice / 中国实验方剂学杂志

Objective:To explore the underlying protective mechanism of Kaixinsan on learning， memory， and synaptic function in APP/PS1 mice. Method:Sixty APP/PS1 mice were randomly divided into a model group， a donepezil （2 mg·kg^-1·d^-1） group， and low- （0.7 g·kg^-1·d^-1）， medium- （1.4 g·kg^-1·d^-1）， and high-dose （2.8 g·kg^-1·d^-1） Kaixinsan groups， and the wild-type mice of the same age in the same litter were assigned to the normal group， with 12 mice in each group. After continuous intragastric administration for two months， the Morris water maze experiment was performed. The ultrastructure of hippocampal neurons was observed by transmission electron microscopy. The colorimetric assay was used to detect serum content of acetylcholine （ACh）， choline acetyltransferase （ChAT）， acetylcholinesterase （AChE）， and levels of hippocampal reactive oxygen species （ROS）， malondialdehyde （MDA）， superoxide dismutase （SOD）， and glutathione peroxidase （GSH-Px）. Real-time fluorescence-based quantitative polymerase chain reaction （Real- time PCR） was used to detect the mRNA expression of hippocampal brain-derived neurotrophic factor （BDNF）， beta-nerve growth factor （NGFB）， discs large homolog (DLG)2， DLG4， and synaptophysin （SYP）. Result:Compared with the normal group， the model group showed prolonged escape latency， reduced number of crossing platforms， shortened stay in the target quadrant （<italic>P</italic><0.01）， decreased number of mitochondria with different shapes and irregular arrangement， some swollen and deformed mitochondria with broken mitochondrial cristae， endolysis， and cytoplasm vacuole， and more cell debris. Additionally， the model group also displayed reduced serum levels of ACh and ChAT， increased AChE （<italic>P</italic><0.01）， elevated hippocampal ROS and MDA （<italic>P</italic><0.05，<italic>P</italic><0.01）， declining SOD and GSH-Px （<italic>P</italic><0.01）， and diminished hippocampal BDNF， NGFB， DLG2， DLG4， and SYP mRNA levels （<italic>P</italic><0.05，<italic>P</italic><0.01）. Compared with the model group， the donepezil group， and the medium- and high-dose Kaixinsan groups showed shortened escape latency， increased number of crossing platforms， prolonged stay in the target quadrant （<italic>P</italic><0.05，<italic>P</italic><0.01）， improved mitochondrial damage with a regular shape （mainly oval shape）， relieved mitochondrial swelling and deformation， and clear mitochondrial cristae. Furthermore， the donepezil group， and the medium- and high-dose Kaixinsan groups also exhibited increased serum ACh and ChAT levels （<italic>P</italic><0.05，<italic>P</italic><0.01）， blunted AChE activity （<italic>P</italic><0.05）， reduced hippocampal ROS level （<italic>P</italic><0.05，<italic>P</italic><0.01）， declining MDA level （<italic>P</italic><0.05）， potentiated SOD and GSH-Px activities， and up-regulated hippocampal BDNF， NGFB， DLG2， DLG4， and SYP mRNA levels （<italic>P</italic><0.05，<italic>P</italic><0.01）. In the low-dose Kaixinsan group， the stay time in the target quadrant was prolonged and the expression of hippocampal SYP mRNA was elevated significantly （<italic>P</italic><0.05）. There was no statistical difference in swimming speed between the groups. Conclusion:Kaixinsan can improve the learning and memory ability of APP/PS1 mice by increasing the expression of synaptic plasticity-related proteins， reducing the ultrastructural damage to hippocampal neurons， resisting oxidative stress， and regulating cholinergic neurotransmitters， thereby exerting neuroprotective effects.

Effect of Bushen Tongluo Prescription on Synaptic Plasticity of Hippocampal Neurons of Vascular Dementia Model Rats Based on PI3K/Akt/mTOR Pathway / 中国实验方剂学杂志

Objective:To explore the effect of Bushen Tongluo prescription （BSTLP） on the synaptic plasticity of hippocampal neurons in vascular dementia （VD） model rats and its mechanism. Method:SD male rats of SPF grade were selected. The rat model of VD was established by permanent bilateral ligation of the common carotid artery several times. The model rats were randomly divided into a model group， an insulin-like growth factor-1 （IGF-1， 20 μg·kg^-1） group， high-dose （3 g·kg^-1）， medium-dose （1.5 g·kg^-1）， and low-dose （0.75 g·kg^-1） BSTLP groups. A sham operation group was also set. Drugs were administered to rats by gavage once a day for four weeks. The model group and the sham operation group received the same volume of normal saline. After the last administration， all the rats were detected for spatial learning and memory by the Morris water maze. The apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase （TdT） dUTP nick-end labeling （TUNEL） assay. The changes in synaptic morphological structure and the number of dendritic spines in hippocampal neurons were detected by Golgi's method. The expression levels of phosphatidylinositol 3-kinase （PI3K）， protein kinase B （Akt）， mammalian target of rapamycin （mTOR）， synaptophysin （SYP）， and amyloid precursor protein （APP） in hippocampal neurons were detected by Western blot. Result:Compared with the sham operation group， the model group showed prolonged escape latency， lengthened swimming distance， dwindled the number of times for the platform crossing after platform removal （<italic>P</italic><0.05）， increased apoptotic cells （<italic>P</italic><0.05）， declining synaptic dendritic spines （<italic>P</italic><0.05）， down-regulated expression levels of PI3K， Akt， mTOR， and SYP proteins， and up-regulated expression level of APP protein in hippocampal neurons （<italic>P</italic><0.05）. Compared with the model group， the BSTLP groups and the IGF-1 group showed shortened escape latency and swimming distance， increased number of times for the platform crossing after platform removal （<italic>P</italic><0.05），declining apoptotic cells （<italic>P</italic><0.05）， up-regulated expression levels of PI3K， Akt， mTOR， and SYP proteins， and down-regulated expression level of APP protein in hippocampal neurons （<italic>P</italic><0.05）. Compared with the IGF-1 group， the high-dose BSTLP group showed no significant difference in the escape latency， swimming distance， the number of times for the platform crossing after platform removal， apoptotic cells， synaptic dendritic spines， and expression levels of PI3K， Akt， mTOR， SYP， and APP proteins in hippocampal neurons. However， the differences were significant in the medium-dose and low-dose BSTLP groups （<italic>P</italic><0.05）. Conclusion:BSTLP can improve the learning and memory of rats with VD. The mechanism is presumedly related to the activation of thePI3K/Akt/mTOR pathway and improvement of synaptic plasticity of hippocampal neurons.

Mechanism of Sleep Deprivation and Cognitive Impairment and Research Progress of Traditional Chinese Medicine Intervention / 中国实验方剂学杂志

Adequate sleep is an important factor to ensure the healthy functioning of the body. A type of chronic sleep diseases characterized by insufficient sleep can be collectively referred to as sleep deprivation （SD）， which is divided into primary and secondary sources in terms of sources. As one of the most frequent types of diseases in recent years， SD has received more and more attention and attention from the whole society. SD can have a wide-ranging and far-reaching impact on cognitive behavior， such as decreased wakefulness， decreased alertness， and inattention， decreased sensory perception， decreased learning and memory capabilities， et al， involving the impact on multiple system functions of the human body， and It is closely related to the occurrence of many diseases， and may cause serious troubles to the normal life of patients and even their relatives and friends. The cognitive impairment caused by SD has been fully verified in clinical tests and various animal behavior experiments， mainly involving pathological damage such as changes in synaptic plasticity， enhanced endoplasmic reticulum stress， circadian rhythm disorders， and energy metabolism imbalance. Western medicine treatments for SD mostly have negative factors such as high side effect and strong addiction. However， Chinese medicine intervention focuses on the overall concept， has long-lasting effectiveness， significant effects， and mild side effects. It has also been widely recognized clinically for improving the complications of sleep disorders. This article reviews the current status and classification of SD research， its pathological mechanisms that lead to cognitive impairment and its molecular-level exploration directions and results. In recent 5 years， the therapeutic effect and experience of traditional Chinese medicine intervention therapy such as compound Chinese medicine， acupuncture and moxibustion as well as auxiliary therapy such as exercise and five sounds， in order to further summarize and clarify the interaction mechanism between SD and cognitive behavior， and provide a theoretical basis for the study of the pathological mechanism of SD disease and future clinical treatment.

Research progress on the effect of transcranial magnetic stimulation on learning, memory and plasticity of brain synaptic / 生物医学工程学杂志

Transcranial magnetic stimulation (TMS) as a noninvasive neuromodulation technique can improve the impairment of learning and memory caused by diseases, and the regulation of learning and memory depends on synaptic plasticity. TMS can affect plasticity of brain synaptic. This paper reviews the effects of TMS on synaptic plasticity from two aspects of structural and functional plasticity, and further reveals the mechanism of TMS from synaptic vesicles, neurotransmitters, synaptic associated proteins, brain derived neurotrophic factor and related pathways. Finally, it is found that TMS could affect neuronal morphology, glutamate receptor and neurotransmitter, and regulate the expression of synaptic associated proteins through the expression of brain derived neurotrophic factor, thus affecting the learning and memory function. This paper reviews the effects of TMS on learning, memory and plasticity of brain synaptic, which provides a reference for the study of the mechanism of TMS.

Effect of Baihe Dihuang Decoction on synaptic plasticity of hippocampus in rats with anxious depression / 中国中药杂志

To explore the effect of Baihe Dihuang Decoction on the synaptic plasticity of hippocampal neurons in rats with anxious depression. Fifty SD rats were randomly divided into normal group, model group, venlafaxine group(6.75 mg·kg~(-1)), high-dose Baihe Dihuang Decoction group(8.64 g·kg~(-1)) and low-dose Baihe Dihuang Decoction group(4.32 g·kg~(-1)). Chronic restraint stress(6 h) combined with corticosterone(ih, 30 mg·kg~(-1)) was used to establish an anxious depression model, and 7 days after modeling, the administration started and continued for 21 days. The anxiety and depression-like behaviors of the rats were evaluated. Golgi-Cox staining and electron microscopy were used to observe the morphology and ultrastructural changes of synaptic dendrites. Immunofluorescence was used to detect the expression of hippocampal synaptic plasticity protein synapsin-1 and postsynaptic density protein 95(PSD-95). Western blot method was used to detect the expression of functional protein synaptophysin(SYP) and synaptic Ras GTPase activating protein(SynGap). The results showed that the rats in the model group had obvious anxiety and depression-like behaviors, the hip-pocampal dendritic spine density and branch length were reduced, the number of synapses was cut, and the internal structure was da-maged. The average fluorescence intensity of synapsin-1 and PSD-95 was significantly reduced and the expression of SYP and SynGap also decreased. High-dose Baihe Dihuang Decoction could significantly improve the anxiety and depression-like behaviors of model rats, relieve synaptic damage, and increase the expression of synapsin-1, PSD-95, SYP, and SynGap proteins. Therefore, we believe that Baihe Dihuang Decoction can improve anxiety and depression behaviors by regulating the synaptic plasticity of hippocampal neurons.

Steroid Receptor Coactivator 3 Regulates Synaptic Plasticity and Hippocampus-dependent Memory / 神经科学通报·英文版

Steroid hormones play important roles in brain development and function. The signaling of steroid hormones depends on the interaction between steroid receptors and their coactivators. Although the function of steroid receptor coactivators has been extensively studied in other tissues, their functions in the central nervous system are less well investigated. In this study, we addressed the function of steroid receptor coactivator 3 (SRC3) - a member of the p160 SRC protein family that is expressed predominantly in the hippocampus. While hippocampal development was not altered in Src3

Cranial irradiation alters dendritic spine density and morphology in the young rat hippocampus / 中华放射医学与防护杂志

Objective:To explore the changes of dendritic spine morphology and structure in dentate gyrus(DG) and CA1 areas of hippocampus of young rats, so as to provide a direct morphological basis for studying the molecular mechanism of radiation cognitive impairment.Methods:21-day-old Sprague-Dawley (SD) rats were given a single dose of 10 Gy whole brain irradiation. The changes of cognitive function, dendritic spine density and morphological changes in DG and CA1 areas of hippocampus were observed 1 and 3 months after irradiation, and the expression of postsynaptic density protein (PSD95) was detected by Western blot.Results:The cognitive impairment was observed in young rats 3 months after irradiation. The density of dendritic spines in DG area of hippocampus was decreased significantly by 39.06% and 29.27% at 1 and 3 months after irradiation ( t=14.96, 12.35, P<0.05), respectively. The density of dendritic spines in the basal dendrites of hippocampal CA1 area was decreased by 33.40% ( t=10.39, P<0.05) 1 month after irradiation, but had no significant change at 3 months after irradiation. While the density of dendritic spines in the apical dendrites of CA1 region did not change significantly at 1 and 3 months after irradiation. In addition, the morphology of dendritic spines in DG and CA1 regions of hippocampus was dynamically changed after irradiation. The expression of PSD95 protein was decreased by 24.6% and 50.5% ( t=2.97, 9.27, P<0.05) at 1 and 3 months after irradiation, respectively. Conclusions:This study reported the density and morphological changes of dendritic spines in different brain regions of hippocampus of young rats after ionizing radiation, suggesting that PSD95 may participate in the occurrence of radiation-induced cognitive impairment by affecting the structure and morphology of dendritic spines and reducing synaptic plasticity.