姜黄素可阻止白细胞介素6损伤海马神经元钙离子的快速内流

The current study sought to investigate the potential protective action of curcumin against interleukin-6-induced injury in rat hippocampal neurons.The results revealed that interleukin-6 induced typical cellular injury,such as the swelling of cell bodies and increased Ca2+ concentration.After administration of curcumin,interleukin-6-induced neurons recovered to a normal state,and the fluorescence intensity of Ca2+ gradually returned to normal.These findings suggest that curcumin exerts a protective effect on hippocampal neurons of rats.In addition,our results suggest that the protective effect of curcumin involves prevention of the rapid Ca2+ influx induced by interleukin-6,which maintains Ca2+ homeostasis.     

急性癫痫大鼠海马CA3区Bcl-2表达及线粒体改变

BACKGROUND： Previous studies have shown that the mitochondrial structure and function are damaged in animal models of epilepsy. In addition, the Bcl-2 protein is capable of regulating mitochondrial stability. OBJECTIVE： To observe and validate changes in mitochondrial structure and Bcl-2 expression, and to analyze these characteristics in the hippocampal CA3 region of rat models of epilepsy. DESIGN, TIME AND SETTING： This randomized, controlled, animal experiment was performed at the Laboratory of Electron Microscopy and Department of Histology and Embryology, Luzhou Medical College between 2007 and 2008. MATERIALS： Coriamyrtin was provided by the Pharmacy Factory of West China University of Medical Sciences. The primary and secondary antibodies were provided by Zhongshan Goldenbridge Biotechnology, Beijing. METHODS： A total of 44 adult, male, Sprague Dawley rats were randomly divided into control （n = 11） and epilepsy （n = 33） groups. Rats in the epilepsy group were induced by coriamyrtin （50 μ g/kg）, which was injected into the lateral ventricles. The rats were then observed at 3, 6, and 24 hours after epilepsy induction, with 11 rats at each time point. Epilepsy was not induced in rats from the control group. MAIN OUTCOME MEASURES： Pathological changes in the hippocampal CA3 region were observed by light microscopy; Bcl-2 expression was analyzed by immunohistochemistry; and mitochondrial changes in the hippocampus were observed under transmission electron microscopy. RESULTS： （1） The control group displayed very little Bcl-2 protein expression in the hippocampal CA3 region. However, after 3 hours of epilepsy, expression was visible. By 6 hours, expression peaked and then subsequently decreased after 24 hours, but remained higher than the control group （P 〈 0.05）. （2） Mitochondria were damaged to varying degrees in the epilepsy groups. For example, mitochondria edema, cristae space increase, and disappearance of mitochondria were apparent. Moreover, mitochondrial damage occurred prior to pathological changes in the neurons and nucleolus. CONCLUSION： Bcl-2 expression and mitochondrial damage increased in the hippocampal CA3 region in rats with epilepsy. Moreover, mitochondrial damage occurred prior to increased Bcl-2 expression and nucleolus damage.     

Cover Figure

Curcumin exerts a protective effect on hippocampal neurons of rats. In addition, the protective effect of curcumin involves prevention of the rapid Ca2+ influx induced by interleukin-6,which maintains Ca2+ homeostasis. This image shows many axons, dendrites and     

马桑内酯激活星形胶质细胞条件培养液对大脑皮质及海马神经元雌、孕激素受体的影响

BACKGROUND： Coriaria lactone-activated astrocytes released bioactive substances that eventually caused epilepsy.
OBJECTIVE： It has been suggested that activated astrocytes alter the expression of the estrogen receptor and progesterone receptor by releasing bioactive substances during epilepsy, thereby affecting neuronal activity in the brain. This study was designed to observe the expression of the estrogen receptor and the progesterone receptor in rat brain following lateral ventricle injection of coriaria lactone-activated, astrocyte-conditioned medium.
DESIGN AND SETTING： This immunohistochemical, randomized, controlled, animal study was conducted at the Department of Pathology, Hospital Affiliated to Binzhou Medical College, China.
MATERIAL： Coriaria lactone was provided by Huaxi Pharmaceutical Factory, China. METHODS： Forty adult, healthy, male, Sprague Dawley rats were randomly assigned into two groups. Astrocyte-conditioned medium （10 μ L） was injected into rat lateral ventricle in the control group （n = 8）. Coriaria lactone-activated, astrocyte-conditioned medium （10 μL） was infused into the rat lateral ventricle in the coriaria lactone group （n = 32）. At 2, 4, 8 and 12 hours following injection, rats were sacrificed and subjected to immunohistochemistry. Eight rats were studied at each time point.
MAIN OUTCOME MEASURES： Behavioral changes were observed in rats of both groups. Expression of the estrogen receptor and the progesterone receptor in rat cortical and hippocampal neurons was measured using immunohistochemistry.
RESULTS： Four hours after injection, estrogen receptor levels in rat cortical and hippocampal neurons were significantly higher in the coriaria lactone group than in the control group （P 〈 0.05）. Progesterone receptor levels were significantly lower in the coriaria lactone group than in the control group （P 〈 0.05）. Seizures were not observed in the control group. In the coriaria lactone group, convulsions appeared 30 minutes after injection; seizures reached grade Ⅲ at 45 minutes rat behavior was nearly normal at 2 hours.
CONCLUSION： Activated astrocytes can induce seizures in the rat by enhancing estrogen receptor expression and decreasing progesterone receptor expression in cerebral cortical and hippocampal neurons.     

Amentoflavone protects hippocampal neurons: anti-inflammatory,antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.     

Both endogenous and exogenous ACh plays antinociceptive role in the hippocampus CA1 of rats

Summary. The present study examines the effect of acetylcholine (ACh), muscarinic acetylcholine receptors (mAChRs) agonist pilocarpine and mAChRs antagonist atropine on the pain-evoked response of pain-excited neurons (PEN) and pain-inhibited neurons (PIN) in the hippocampal CA1 of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. The discharges of PEN and PIN in the hippocampal CA1 were recorded by glass microelectrode. The results showed that intrahippocampal microinjection of ACh (2 μg/1 μl) or pilocarpine (2 μg/1 μl) decreased the frequency of discharge of PEN, and increased the frequency of discharge of PIN evoked by the noxious stimulation in the hippocampal CA1, while intrahippocampal administration of atropine (0.5 μg/1 μl) produced opposite response. On the basis of the above findings, we can deduce that ACh and mAChRs are involved in the modulation of nociceptive information transmission in the hippocampal CA1. Correspondence: Man-Ying Xu, Department of Physiology, Harbin Medical University, Harbin 15 0081, Heilongjiang Province, China     

Effects of MCI-186 on intracellular calcium ion concentration and membrane fluidity of hippocampal neurons in a rat model of Alzheimer's disease

The present study observed the effects of MCI-186 on the intracellular calcium ion concentra-tion ([Ca2+]i) and membrane fluidity of hippocampal neurons in Alzheimer’s disease (AD) model rats to validate the neuroprotective effects of MCI-186.Compared with normal and sham-operated rats,the escape latency was obviously prolonged,spanning platform times were obviously reduced,[Ca2+]i was increased,and microviscosity η value was increased in AD rats.MCI-186 at 0.5 mg/mL and 0.2 mg/mL obviously shortened escape latency,increased spanning platform times and decreased [Ca2+]i and microviscosity η values in AD rats at 7 and 17 days after induction of the model.The differences in the above-mentioned indices between normal and MCI-186-treated rats were statistically significant.MCI-186 at 0.2 mg/mL yielded better curative effects than 0.5 mg/mL MCI-186.These findings suggest that MCI-186 improves learning and memory abilities in AD rats by decreasing [Ca2+]i and increasing membrane fluidity of hippocampal neurons.     

海马神经元癫癎样放电模型中神经元凋亡的研究

目的通过检测体外海马神经元癫癎样放电后的细胞凋亡,旨在探讨颞叶癫癎病人海马神经元丢失的机制.方法首先制备Sombati神经元癫癎样放电模型,然后采用Tunel标记、荧光染色以及流式细胞技术对模型中的凋亡神经元作了定性和定量检祆测.结果发现神经元癫癎样放电后出现细胞凋亡,且随着放电时间的延长,凋亡细胞增加.结论反复癫癎样放电导致神经元凋亡,其发生可能与癫癎样放电的兴奋性毒性有关.     

Influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein in primary hippocampal neurons★

BACKGROUND： The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE： To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein （Gi2 protein） in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING： A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS： Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate （Avidin-FITC） was purchased from Sigma Company （USA） and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company （USA）. METHODS： Seven days after culture, mature hippocampal neurons were randomly divided into six groups： 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine （10 μ mol/L）, which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES： Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS： Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group （P 〈 0.05 0.01）. CONCLUSION： Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.     

丹参诱导大鼠骨髓间充质干细胞分化为神经元样细胞中的钙离子检测

目的 检测大鼠骨髓间充质干细胞经丹参注射液诱导分化的神经元样细胞内钙离子浓度,以期为骨髓间充质干细胞应用于神经系统疾病的治疗提供理论依据.方法 从成年大鼠骨髓中获取骨髓间充质干细胞,体外扩增培养,经碱性成纤维生长因子预诱导后施加10mL/L丹参注射液于骨髓间充质干细胞培养液中.运用免疫荧光检测神经元特异性核蛋白(NeuN)在诱导后细胞与经新生大鼠海马获取的体外培养海马神经元中的表达.激光共聚焦技术检测诱导后的细胞内钙离子浓度.并与原代培养海马神经元内的钙离子浓度进行比较.结果 大鼠骨髓间充质干细胞经碱性成纤维生长因子和丹参注射液处理后,可表达NeuN,并具有神经元样的表型.诱导分化的神经元样细胞内钙离子浓度为984.75±79.51,原代培养海马神经元内钙离子浓度为769.42±60.93,两者比较差异无统计学意义(P>0.05).结论 丹参注射液诱导骨髓间充质干细胞分化的神经元样细胞具有神经元的某些特征.     

低镁诱发急性海马切片高兴奋性的多电极记录

目的 多电极记录技术在脑片研究的应用已经远远超过了10年,然而该技术却没有广泛地用于癫痫领域的研究。用经典的致痫剂低镁人工脑脊液灌流大鼠急性海马切片,诱导产生癫痫样电活动并用多电极记录技术对其放电特征及内部传导方式进行分析。 方法 用多电极阵列持续记录灌流低镁人工脑脊液后海马各区域的放电情况,并比较切断CA3与CA1区域间的Schaffer氏纤维后各区的放电情况。 结果 在急性海马切片上诱导出自发、同步、癫痫样电活动;CA3区神经元簇发放电持续时间及簇发放电内动作电位的个数与CA1及DG区相比有显著的统计学差异;剪断CA3与CA1间的Schaffer氏纤维后,CA1区的电活动消失,CA3区仍有同步放电,且其自发同步放电的频率与对照组相比无显着改变,但其簇发放电持续时间及簇发放电内动作电位的个数明显降低（P<0.05）。 结论 成功地在多电极上记录到急性海马切片自发、同步、癫痫样电活动;其中CA3区神经元兴奋性最高;在低镁灌流下自发癫痫样电活动起源于CA3区,在剪断Schaffer氏侧支后CA3区神经元群体同步放电的频率的频率没有显着变化。     

低镁诱发急性海马切片高兴奋性的多电极记录

目的 多电极记录技术在脑片研究的应用已经远远超过了10年,然而该技术却没有广泛地用于癫痫领域的研究。用经典的致痫剂低镁人工脑脊液灌流大鼠急性海马切片,诱导产生癫痫样电活动并用多电极记录技术对其放电特征及内部传导方式进行分析。 方法 用多电极阵列持续记录灌流低镁人工脑脊液后海马各区域的放电情况,并比较切断CA3与CA1区域间的Schaffer氏纤维后各区的放电情况。 结果 在急性海马切片上诱导出自发、同步、癫痫样电活动;CA3区神经元簇发放电持续时间及簇发放电内动作电位的个数与CA1及DG区相比有显著的统计学差异;剪断CA3与CA1间的Schaffer氏纤维后,CA1区的电活动消失,CA3区仍有同步放电,且其自发同步放电的频率与对照组相比无显着改变,但其簇发放电持续时间及簇发放电内动作电位的个数明显降低（P<0.05）。 结论 成功地在多电极上记录到急性海马切片自发、同步、癫痫样电活动;其中CA3区神经元兴奋性最高;在低镁灌流下自发癫痫样电活动起源于CA3区,在剪断Schaffer氏侧支后CA3区神经元群体同步放电的频率的频率没有显着变化。     

氟桂利嗪对青霉素致痈效应和海马神经元单位放电的影响

目的：探讨Ca^2＋拮抗剂氟桂利嗪对青霉素致效应和海马神经元单位放电的影响.方法：Wistar大鼠随机分成3组.正常对照组;癫癎模型组：用青霉素钠按6 000 000 U·kg^-1腹腔注射;癫癎预处理组：造模前用盐酸氟桂利嗪 20 mg·kg^-1每隔12 h灌胃,共2次,于第2次给药2 h后制作模型.观察癫癎发作并记录海马神经元单位放电.结果： ①正常对照组大鼠共记录到24个单位海马神经元放电;②癫癎模型组共记录到78个单位海马神经元放电,癫癎发作程度强,发作频率高;③癫癎预处理组共记录到47个单位海马神经元放电,癫癎发作程度减轻,发作频率减少.结论：氟桂利嗪可抑制青霉素致效应,减少海马神经元的单位放电.     

Activity of septal and hippocampal neurons during isolated and combined growth in the anterior chamber of the eye in the rat

Neuronal activity of the septal and hippocampal grafts, developing in the anterior eye chamber of the rat for 3-6 months was recorded extracellularly in curarized or cerveau isolé animals. While the units of isolated septum had background activity of regular, irregular and rhythmic burst type, the hippocampal units displayed no background discharges or produced very low-frequency population spikes. In the paired septal-hippocampal grafts neurons of the hippocampus possessed the same types of activity, as that of the septum. Spontaneous epileptiform phenomena were observed in many paired grafts; such phenomena were easily provoked by mild electrical stimulation of one of the grafts. Superfusion with low Ca2+, high Mg2+ medium abolished spontaneous activity in most of hippocampal units but not in septal units. Epileptic discharges were also partly suppressed.     

Electrophysiological properties of neurons in the rostral ventrolateral medulla of normotensive and spontaneously hypertensive rats

Single unit activities were recorded from the rostral ventrolateral medulla (RVL) of pentobarbital-anesthetized normotensive Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Throughout the recording period, arterial blood pressures of WKY (mean arterial pressure, MAP = 103.1 mm Hg) and SHR (MAP = 159.2 mm Hg) remained stable at the respective basal levels. The units recorded in this study were all spontaneously active and cardiac-locked. Two types of discharge patterns, namely single and double discharges, were identified. These single and double discharge units were found to distribute randomly in RVL. In WKY, 92.6% of RVL neurons exhibited single discharges whereas in SHR, the majority (57%) of RVL neurons exhibited double discharges. The mean firing rate of single discharge units in RVL of SHR was significantly higher than that of WKY, whereas the mean firing rate of double discharge units in WKY was similar to that of SHR. About half of the units studied were also tested for antidromic collision; all units tested could be antidromically activated from the intermediolateral column (IML) of the thoracic spinal cord and the lowest threshold sites were consistently localized within IML. In both groups of rats, the axonal conduction velocity of RVL neurons showed a bimodal distribution viz. the fast and slow conducting axons. The mean conduction velocities of each of these two groups of neurons in WKY and SHR were similar. Most of the double discharge units in WKY and SHR belonged to the fast conducting type.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sombati癫癎细胞模型电压依赖性钾电流的变化

目的：采用全细胞膜片钳记录技术研究Sombati癫癎细胞模型电压依赖性K＋电流的变化。方法：取SD新生乳鼠双侧海马,体外原代培养海马神经元,培养至第9天的部分海马神经元经无镁液处理3h制备癫癎细胞模型,采用全细胞膜片钳技术分别记录正常组（未经无镁液处理的海马神经元）和致癎组（经无镁液处理3h后更换为正常维持培养液的海马神经元）海马神经元的电压依赖性外向K＋电流。结果：致癎组外向K＋电流比正常组增大,峰值电流由（596.62±79.23）pA增至（978.68±53.23）pA,两组间比较差异有统计学意义（P=0.000）。与正常组相比,致癎组的I-V曲线明显左移,I-V曲线形态无显著改变。结论：Sombati癫癎细胞模型中,电压依赖性外向K＋电流显著增加可能是癫癎细胞模型癎性放电后为了保持细胞稳态的代偿性保护作用。     

慢性癫癎模型海马神经元内钙稳态和钙动力学的长期变化

目的 探讨海马神经元内长期钙离子([Ca2+]i)和动力学变化在癫疴发生机制中的作用.方法 建立氯化锂-匹罗卡品慢性癫癎模型,于致痫后6 h和1、3、7、14、30 d不同时间点应用激光共聚焦显微镜观察离体海马神经元内[Ca2+]i的变化以及谷氨酸负荷后神经元内[Ca2+]i恢复速度的变化.结果 正常对照组大鼠急性分离海马神经元[Ca2+]i为(95.4±22.1)nmol/L,致癎后急剧升高至(867.6±35.2)nmol/L,第7天降低(292.8±18.3)mnol/L,此后持续在此水平,30 d后降至(220.8±17.6)nmol/L,仍高于对照组(t=12.55,P<0.01);正常对照组大鼠92%的海马神经元内[Ca2+]i处于正常范围内(25～150 nmol/L),致癎后6 h,所有神经元[Ca2+]i均有升高,并且85%的神经元高于500 nmol/L,致癎7、14、30 d后分别有75%、60%、52%的神经元[Ca2+]i高于正常值,但高于500 nmol/L者逐渐减少;经接触5 μmol/L谷氨酸人工脑脊液2 min后,对照组神经元可在(9.5±3.4)min内恢复至基线水平,而急性期、潜伏期、慢性期的癫癎神经元均存在明显延迟(t=5.08、4.56、4.21,P<0.01).结论 氯化锂-匹罗卡品致疴后可造成海马神经元内长期的[Ca2+]i和钙动力学改变,该种长期可塑性改变在慢性癫癎模型的诱发和维持中起着重要作用.     

凋亡诱导因子在戊四氮致痫大鼠海马组织中的表达

目的研究凋亡诱导因子(AIF)mRNA在戊四氮(PTZ)点燃癫痫持续状态(SE)大鼠海马组织中的表达情况。方法通过腹腔注射戊四氮建立急性点燃大鼠模型,运用逆转录聚合酶链反应技术(RT-PCR)分析AIFmRNA在大鼠癫痫发作后的表达情况。结果癫痫发作后海马组织AIFmRNA的表达水平早期即出现升高(6h组与对照组相比,P<0.05),且持续较长一段时间(48h组与对照组相比,P<0.01)。结论AIF可能参与了戊四氮致痫大鼠海马神经元的凋亡过程。