Repetitive transcranial magnetic stimulation promotes neurological functional recovery in rats with traumatic brain injury by upregulating synaptic plasticity-related proteins

Studies have shown that repetitive transcra nial magnetic stimulation(rTMS)can enhance synaptic plasticity and improve neurological dysfunction.Howeve r,the mechanism through which rTMS can improve moderate traumatic brain injury remains poorly understood.In this study,we established rat models of moderate traumatic brain injury using Feeney's weight-dropping method and treated them using rTMS.To help determine the mechanism of action,we measured levels of seve ral impo rtant brain activity-related proteins and their mRNA.On the injured side of the brain,we found that rTMS increased the protein levels and mRNA expression of brain-derived neurotrophic factor,tropomyosin receptor kinase B,N-methyl-D-aspartic acid receptor 1,and phosphorylated cAMP response element binding protein,which are closely associated with the occurrence of long-term potentiation.rTMS also partially reve rsed the loss of synaptophysin after injury and promoted the remodeling of synaptic ultrastructure.These findings suggest that upregulation of synaptic plasticity-related protein expression is the mechanism through which rTMS promotes neurological function recovery after moderate traumatic brain injury.

Chronic Kidney Disease Induces Cognitive Impairment in the Early Stage

Objective Previous research indicates a link between cognitive impairment and chronic kidney disease(CKD),but the underlying factors are not fully understood.This study aimed to investigate the progression of CKD-induced cognitive impairment and the involvement of cognition-related proteins by developing early-and late-stage CKD models in Sprague-Dawley rats.Methods The Morris water maze test and the step-down passive avoidance task were performed to evaluate the cognitive abilities of the rats at 24 weeks after surgery.Histopathologic examinations were conducted to examine renal and hippocampal damage.Real-time PCR,Western blotting analysis,and immunohistochemical staining were carried out to determine the hippocampal expression of brain-derived neurotrophic factor(BDNF),choline acetyltransferase(ChAT),and synaptophysin(SYP).Results Compared with the control rats,the rats with early-stage CKD exhibited mild renal damage,while those with late-stage CKD showed significantly increased serum creatinine levels as well as apparent renal and brain damage.The rats with early-stage CKD also demonstrated significantly impaired learning abilities and memory compared with the control rats,with further deterioration observed in the rats with late-stage CKD.Additionally,we observed a significant downregulation of cognition-related proteins in the hippocampus of rats with early-stage CKD,which was further exacerbated with declining renal function as well as worsening brain and renal damage in rats with late-stage CKD.Conclusion These results suggest the importance of early screening to identify CKD-induced cognitive dysfunction promptly.In addition,the downregulation of cognition-related proteins may play a role in the progression of cognitive dysfunction.

锁阳乙酸乙酯提取物的雌激素样作用研究

雌激素提高学习记忆能力的功能已被广泛承认,前期实验证实锁阳乙酸乙酯提取物(ECS)可表现出雌激素样作用,提高去卵巢大鼠的学习记忆能力及血清E2水平,对Aβ损伤SK-N-SH细胞有一定的保护作用。为了进一步研究ECS的雌激素样作用机制,拟在小鼠神经母细胞瘤细胞(Neuro2A)上探寻ECS对学习记忆相关蛋白突触素蛋白synaptophysin和环磷腺苷效应元件结合蛋白表达影响。采用CCK8法测定ECS对小鼠神经母细胞瘤细胞(Neuro2A)细胞活力的影响。将小鼠神经母细胞瘤细胞分为正常组、DMSO组、ECS组、Tamoxifen组、Tamoxifen+ECS组;正常组、ECS组、ECS+G15组和正常组、DMSO组、ECS组、PD98059组、PD98059+ECS组。采用Western blot法测定synaptophysin,p-creb蛋白表达情况。实验表明锁阳乙酸乙酯提取物可促进synaptophysin,P-CREB表达,ER受体竞争性拮抗剂Tamoxifen可降低synaptophysin表达,对ECS促进synaptophysin表达无显著影响。GPR30受体特异性阻断剂G15可显著降低ECS促进synaptophysin表达。p-CREB上游Erk1/2-MAPK通路的阻断剂PD98059可显著抑制ECS上调p-CREB表达,结合前期实验结果,我们认为ECS可与GPR30结合通过MAPK通路促进学习记忆相关蛋白synaptophysin表达。

慢性给予应激水平的糖皮质激素对海马神经元和突触的影响

为探讨慢性给予应激水平糖皮质激素对大鼠海马的影响,在实验组大鼠饮用水中加入皮质醇,使动物皮质醇吸收量达每日10mg/kg,从而引起与应激动物相同的皮质醇水平,共21d,然后用免疫组织化学和免疫印迹法观察海马内caspase-3、synap-tophysin(Syn)和neurogranin(Ng)表达的变化。结果显示:(1)实验组大鼠海马结构中可见较多细胞出现核固缩的病理改变,但未见或偶见极个别caspase-3免疫反应阳性细胞;(2)与正常组Syn表达水平(1.2197±0.3443)和Ng表达水平(1.9330±0.3450)相比,实验组大鼠海马结构中Syn和Ng的表达明显减少(P<0.05),其表达水平分别为0.5512±0.0540和1.3375±0.3317。上述结果表明慢性给予应激水平的糖皮质激素可损伤海马功能,引起不依赖caspase-3的海马神经细胞退变、使海马突触数量减少以及改变海马突触效能可能是其作用的部分机制。

突触后致密蛋白95(PSD95)和突触小泡蛋白在神经元成熟过程中的分布

目的探讨突触后致密蛋白95(PSD95)和突触小泡蛋白(SYP)在原代培养不同时间神经元中的表达。方法采用免疫荧光技术检测原代培养3 d(3DIV)、7DIV和14DIV大脑皮层神经元内的PSD95和SYP的表达。结果 PSD95在3DIV时主要分布在神经元胞体;7DIV时分布在胞体、突起末端和分支处;14DIV时分布在胞体和呈斑点状分布在神经元突起上。SYP在3DIV时无明显表达,7DIV时分布在神经元细胞核内,14DIV时分布在细胞核内和呈斑点状分布在突起上。结论随着培养神经元和突触的发育至成熟,PSD95和SYP最初主要位于神经元胞体和细胞核内,最终大都呈斑点状密集分布在突起上。表明PSD95和SYP虽产生部位不同,但最终都与突触的形成和成熟密切相关。

脑源性神经生长因子抗体对小鼠坐骨神经损伤后脊髓与背根节内Synaptophysin表达的影响

目的探查小鼠坐骨神经压榨损伤后内源性脑源性神经营养因子(brainderivedneuroliophicfactor,BDNF)对Synaptophysin(SYN)在相应脊髓前角运动细胞与背根节神经元内表达的影响。方法在小鼠一侧坐骨神经压榨损伤后腹腔注射BDNF抗体,中和内源性BDNF,然后用免疫组织化学方法观察SYN在与坐骨神经相连的脊髓前角运动细胞与背根节神经元的表达。结果实验组SYN免疫反应阳性神经元的数目较对照组明显减少,阳性细胞的平均光密度也显著下降(P<0.01)。结论小鼠坐骨神经压榨损伤后内源性BDNF可能参与脊髓前角运动细胞与背根节神经元内SYN的表达。

外周输入依赖的嗅球颗粒细胞的突触结构可塑性

活动依赖的突触结构可塑性是学习和记忆的基础.哺乳动物,尤其是啮齿类动物,具有高度发达的嗅觉系统和惊人的气味学习和记忆能力.本研究以CNGA2敲除而导致外周输入缺失的小鼠为模型,研究嗅球内活动依赖的突触结构可塑性.利用特异性的突触前和突触后标记物,发现外周输入缺失减少了突触标记蛋白突触素(synaptophysin)和抑制性突触标记蛋白桥蛋白(gephyrin)在嗅球外网状层和颗粒细胞层中的表达;兴奋性突触标记蛋白囊泡谷氨酸转运蛋白1(VGluT1)的表达水平只在外网状层中有显著下降,而在颗粒细胞层中没有明显变化.进一步通过活体质粒电转标记嗅球颗粒细胞后发现,CNGA2敲除小鼠颗粒细胞上位于外网状层中的远端树突棘密度显著减小,而位于颗粒细胞层中的近端树突棘密度没有明显变化.这些结果表明颗粒细胞上的树-树突触具有对外周活动依赖的结构可塑性,而轴-树突触则无.

嗅鞘细胞条件培养液对PC12细胞神经丝蛋白、突触蛋白、突触素蛋白表达的影响

目的:观察嗅鞘细胞(olfactory ensheathing cells,OECs)条件培养液对PC12细胞神经丝蛋白(neurofilament protein,NF)、突触蛋白(synapsin)和突触素蛋白(synaptophysin)表达的影响,探讨嗅鞘细胞条件培养液促神经细胞分化生长的作用机制。方法:原代培养并纯化OECs,收集培养上清制备成嗅鞘细胞培养液(OEC culture medium,OECCM),与PC12细胞培养24、48、72h,观察细胞形态学变化;通过免疫荧光法检测PC12细胞NF的表达及分布;蛋白质印迹法检测NF、突触蛋白和突触素的相对含量。结果:OECCM培养的PC12细胞长有突起,并随着培养时间的延长,细胞形态酷似神经元;免疫荧光染色显示NF起初在核周分布,OECCM作用后NF的分布范围逐渐增加,其分布面积与β-tubulin分布面积的比值显著增高(P<0.05)。蛋白质印迹法显示OECCM组NF、突触蛋白(synapsin)和突触素蛋白(synaptophysin)的表达水平明显高于对照组(P<0.05)。结论:嗅鞘细胞能分泌一些促PC12细胞分化的因子,这些因子能促进PC12细胞NF骨架的组装,并诱导神经元功能蛋白的表达,使该细胞在结构和功能上向神经元分化。

猴垂体前叶Synaptophysin免疫反应性的光镜观察

目的：为神经纤维对哺乳动物尤其是灵长类动物垂体前叶腺细胞的直接调节作用提供形态学证据．方法：用抗Ｓｙｎａｐｔｏｐｈｙｓｉｎ（ＳＹＮ）单克隆抗体，对ＭａｃａｃａＭｕｌａｔａ猴垂体前叶进行了免疫组化染色．结果：猴垂体前叶ＳＹＮ的免疫反应性主要有膨体型和纤维型两种形式．膨体型表现为大小不等、深染的点状结构．纤维型表现为细、短浅染的ＳＹＮ免疫反应神经纤维，其上分布着大小不等、深染的膨体．ＳＹＮ免疫反应膨体和纤维均分布在腺细胞之间，或沿着细胞团边界走行，与腺细胞密切接触．结论：猴垂体前叶ＳＹＮ免疫反应膨体反映了神经末梢中突触小泡的存在，为“哺乳动物垂体前叶神经体液双重调节的假说”

乳腺癌伴神经内分泌分化与预后因素的相关性

目的:通过观察雌激素受体(ER)、孕激素受体(PR)、Her-2、Ki67在乳腺癌伴神经内分泌分化(nueroendocrine differen-tiation,NED)中的表达,探讨乳腺癌伴NED的预后。方法:选取2000年1月至2009年8月温岭市第一人民医院乳腺癌根治术或改良根治术确诊病例55例,2008年8月-2009年8月温州医学院附属第一医院乳腺癌改良根治术确诊病例35例,根据CgA和Syn免疫组织化学染色结果,分为乳腺癌伴NED阳性和阴性两组。分析两组患者发病年龄、肿块大小、组织学分级、淋巴结转移状态、ER、PR、Her-2、Ki67的表达情况之间的差异。结果:90例患者中NED阳性组33例(占36.67%)。NED阳性组ER、PR阳性表达分别为24例(占72.73%)、21例(占63.64%),明显高于阴性组(P<0.05)。NED阳性组Her-2、Ki67阳性表达分别为11例(占33.33%)、15例(占45.45%),与NED阴性组比差异有统计学意义(P<0.05)。NED阳性组组织学分级为II～III级的患者比例为78.79%,低于NED阴性组92.98%(P<0.05)。NED阳性组淋巴结转移≥1枚的为7例(21.21%),明显低于NED阴性组24例(42.11%,P<0.05)。NED阳性组与NED阴性组间发病年龄及肿块大小的差异无统计学意义(P>0.05)。结论:与不伴NED的乳腺癌相比,乳腺癌伴NED的侵袭性较小,预后好。

Acupuncture accelerates neural regeneration and synaptophysin production after neural stem cells transplantation in mice

BACKGROUND Synaptophysin plays a key role in synaptic development and plasticity of neurons and is closely related to the cognitive process of Alzheimer’s disease(AD)patients.Exogenous neural stem cells(NSCs)improve the damaged nerve function.The effects of Sanjiao acupuncture on cognitive impairment may be related to the regulation of the NSC microenvironment.AIM To explore the anti-dementia mechanism of acupuncture by regulating the NSC microenvironment.METHODS NSCs were isolated from pregnant senescence-accelerated mouse resistant 1(SAMR1)mice,labeled with BrdU,and injected into the hippocampus of senescence-accelerated mouse prone 8(SAMP8)mice.Eight-month-old senescence-accelerated mice(SAM)were randomly divided into six groups:SAMR1(RC),SAMP8(PC),sham transplantation(PS),NSC transplantation(PT),NSC transplantation with acupuncture(PTA),and NSC transplantation with nonacupoint acupuncture(PTN).Morris water maze test was used to study the learning and memory ability of mice after NSC transplantation.Hematoxylin-eosin staining and immunofluorescence were used to observe the histopathological changes and NSC proliferation in mice.A co-culture model of hippocampal slices and NSCs was established in vitro,and the synaptophysin expression in the hippocampal microenvironment of mice was observed by flow cytometry after acupuncture treatment.RESULTS Morris water maze test showed significant cognitive impairment of learning and memory in 8-mo-old SAMP8,which improved in all the NSC transplantation groups.The behavioral change in the PTA group was stronger than those in the other two groups(P<0.05).Histopathologically,the hippocampal structure was clear,the cell arrangement was dense and orderly,and the necrosis of cells in CA1 and CA3 areas was significantly reduced in the PTA group when compared with the PC group.The BrdU-positive proliferating cells were found in NSC hippocampal transplantation groups,and the number increased significantly in the PTA group than in the PT and PTN groups(P<0.05).Flow cytometry showed that after co-culture of NSCs with hippocampal slices in vitro,the synaptophysin expression in the PC group decreased in comparison to the RC group,that in PT,PTA,and PTN groups increased as compared to the PC group,and that in the PTA group increased significantly as compared to the PTN group with acupointrelated specificity(P<0.05).CONCLUSION Acupuncture may promote nerve regeneration and synaptogenesis in SAMP8 mice by regulating the microenvironment of NSC transplantation to improve the nerve activity and promote the recovery of AD-damaged cells.

An enriched environment promotes synaptic plasticity and cognitive recovery after permanent middle cerebral artery occlusion in mice

Cerebral ischemia activates an endogenous repair program that induces plastic changes in neurons. In this study, we investigated the effects of environmental enrichment on spatial learning and memory as well as on synaptic remodeling in a mouse model of chronic cerebral ischemia, produced by subjecting adult male C57 BL/6 mice to permanent left middle cerebral artery occlusion. Three days postoperatively, mice were randomly assigned to the environmental enrichment and standard housing groups. Mice in the standard housing group were housed and fed a standard diet. Mice in the environmental enrichment group were housed in a cage with various toys and fed a standard diet. Then, 28 days postoperatively, spatial learning and memory were tested using the Morris water maze. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 in the hippocampus were analyzed by western blot assay. The number of synapses was evaluated by electron microscopy. In the water maze test, mice in the environmental enrichment group had a shorter escape latency, traveled markedly longer distances, spent more time in the correct quadrant(northeast zone), and had a higher frequency of crossings compared with the standard housing group. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 were substantially upregulated in the hippocampus in the environmental enrichment group compared with the standard housing group. Furthermore, electron microscopy revealed that environmental enrichment increased the number of synapses in the hippocampal CA1 region. Collectively, these findings suggest that environmental enrichment ameliorates the spatial learning and memory impairment induced by permanent middle cerebral artery occlusion. Environmental enrichment in mice with cerebral ischemia likely promotes cognitive recovery by inducing plastic changes in synapses.

Protective effects of Dendrobium nobile Lindl. alkaloids on amyloid beta(25–35)-induced neuronal injury

Dendrobium nobile Lindl.alkaloids（DNLA）,the active ingredients of a traditional Chinese medicine Dendrobium,have been shown to have anti-oxidative effects,anti-inflammatory action,and protective effect on neurons against oxygen-glucose deprivation.However,it is not clear whether DNLA reduces amyloid-beta（Aβ）-induced neuronal injury.In this study,cortical neurons were treated with DNLA at different concentrations（0.025,0.25,and 2.5 mg/L）for 24 hours,followed by administration of Aβ（25-35）（10μM）.Aβ（25-35） treatments increased cell injury as determined by the leakage of lactate dehydrogenase,which was accompanied by chromatin condensation and mitochondrial tumefaction.The damage caused by Aβ（25-35） on these cellular properties was markedly attenuated when cells were pretreated with DNLA.Treatment with Aβ（25-35）down-regulated the expressions of postsynaptic density-95 mRNA and decreased the protein expression of synaptophysin and postsynaptic density-95,all changes were significantly reduced by pretreatment of cells with DNLA.These findings suggest that DNLA reduces the cytotoxicity induced by Aβ（25-35） in rat primary cultured neurons.The protective mechanism that DNLA confers on the synaptic integrity of cultured neurons might be mediated,at least in part,through the upregulation of neurogenesis related proteins synaptophysin and postsynaptic density-95.

Xuefu Zhuyu decoction improves neurological dysfunction by increasing synapsin expression after traumatic brain injury

Xuefu Zhuyu decoction has been used for treating traumatic brain injury and improving post-traumatic dysfunction, but its mechanism of action needs further investigation. This study established rat models of traumatic brain injury by controlled cortical impact. Rat models were intragastrically administered 9 and 18 g/kg Xuefu Zhuyu decoction once a day for 14 or 21 days. Changes in neurological function were assessed by modified neurological severity scores and the Morris water maze. Immunohistochemistry, western blot assay, and re- verse-transcription polymerase chain reaction were used to analyze synapsin protein and mRNA expression at the injury site of rats. Our results showed that Xuefu Zhuyu decoction visibly improved neurological function of rats with traumatic brain injury. These changes were accompanied by increased expression of synaptophysin, synapsin I, and postsynaptic density protein-95 protein and mRNA in a dose-de- pendent manner. These findings indicate that Xuefu Zhuyu decoction increases synapsin expression and improves neurological deficits alder traumatic brain injury.

Combined acupuncture and HuangDiSan treatment affects behavior and synaptophysin levels in the hippocampus of senescence-accelerated mouse prone 8 after neural stem cell transplantation

Sanjiao acupuncture and HuangDiSan can promote the proliferation, migration and differentiation of exogenous neural stem cells in senescence-accelerated mouse prone 8 （SAMP8） mice and can improve learning and memory impairment and behavioral function in dementia-model mice. Thus, we sought to determine whether Sanjiao acupuncture and HuangDiSan can elevate the effect of neural stem cell transplantation in Alzheimer’s disease model mice. Sanjiao acupuncture was used to stimulate Danzhong （CV17）, Zhongwan （CV12）,Qihai （CV6）, bilateral Xuehai （SP10） and bilateral Zusanli （ST36） 15 days before and after implantation of neural stem cells （5 × 10^5） into the hippocampal dentate gyrus of SAMP8 mice. Simultaneously, 0.2 mL HuangDiSan, containing Rehmannia Root and Chinese Angelica,was intragastrically administered. Our results demonstrated that compared with mice undergoing neural stem cell transplantation alone,learning ability was significantly improved and synaptophysin mRNA and protein levels were greatly increased in the hippocampus of mice undergoing both Sanjiao acupuncture and intragastric administration of HuangDiSan. We conclude that the combination of Sanjiao acupuncture and HuangDiSan can effectively improve dementia symptoms in mice, and the mechanism of this action might be related to the regulation of synaptophysin expression.

Ca^(2+)诱导的synaptophysin Ⅰ蛋白的脂筏分布

文章研究了Ca2+对synaptophysin Ⅰ(Syp Ⅰ)蛋白的脂筏分布的影响。研究结果证明,Syp Ⅰ蛋白的脂筏分布明显受到Ca2+的特异性调控。在无Ca2+的条件下,Syp Ⅰ为典型的非脂筏蛋白;而在低浓度Ca2+的条件下,Syp Ⅰ可以转变为脂筏结合蛋白。文章还研究了SypⅠ在Ca2+的诱导下进入脂筏膜微区的分子机制。研究结果表明,Syp Ⅰ在Ca2+的诱导下进入脂筏这一现象依赖于其C末端胞质区,确定了Syp Ⅰ的胞质区在这种调节中的重要性。

Effect of Panax notoginseng saponins on the expression of beta-amyloid protein in the cortex of the parietal lobe and hippocampus, and spatial learning and memory in a mouse model of senile dementia

BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.

Changes in Synapses and Axons Demonstrated by Synaptophysin Immunohistochemistry Following Spinal Cord Compression Trauma in the Rat and Mouse

Objective and methods To evaluate synaptic changes using synaptophysin immunohistochemstry in rat and mouse, which spinal cords were subjected to graded compression trauma at the level of Th8-9. Results Normal animals showed numerous fine dots of synaptophysin immunoreactivity in the gray matter. An increase in synaptophysin immunoreactivity was observed in the neuropil and synapses at the surface of motor neurons of the anterior horns in the ThS-9 segments lost immunoreactivity at 4-hour point after trauma. The immunoreactive synapses reappeared around motor neurons at 9-day point. Unexpected accumulation of synaptophysin immunoreactivity occurred in injured axons of the white matter of the compressed spinal cord. Conclusion Synaptic changes were important components of secondary injuries in spinal cord trauma. Loss of synapses on motor neurons may be one of the factors causing motor dysfunction of hind limbs and formation of new synapses may play an import,ant role in recovery of motor function. Synaptophysin immunohistochemistry is also a good tool for studies of axonal swellings in spinal cord injuries.

Hippocampal expression of synaptic structural proteins and phosphorylated cAMP response element-binding protein in a rat model of vascular dementia induced by chronic cerebral hypoperfusion

The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swimming path length during hidden-platform acquisition training in Morris water maze significantly increased in the model group.In addition,the number of accurate crossings over the original platform significantly decreased,hippocampal CA1 synaptophysin and growth-associated protein 43 expression significantly decreased,cAMP response element-binding protein expression remained unchanged,and phosphorylated cAMP response element-binding protein expression significantly decreased.Results suggested that abnormal expression of hippocampal synaptic structural protein and cAMP response element-binding protein phosphorylation played a role in cognitive impairment following chronic cerebral hypoperfusion.