外伤性脑损伤大鼠学习记忆障碍与海马区突触后致密物蛋白质95表达的关系

目的 观察创伤性脑损伤(traumatic brain injury,TBI)大鼠在Morris水迷宫中学习、记忆能力与大鼠海马区突触后致密物蛋白质95(postsynaptic density 95,PSD - 95)表达变化的关系. 方法 采用完全随机设计将SD大鼠分为TBI组和对照组.TBI组采用冲击加速度脑损伤方式建立模型,通过Morris水迷宫试验观察TBI组和对照组脑损伤后1周的学习、记忆能力,采用免疫蛋白电泳技术观察大鼠海马区脑损伤后1,3,7 d PSD- 95的表达. 结果 与对照组比较,TBI组伤后1周水迷宫逃避潜伏期延长,并且表现较脑损伤后前3d延长明显;蛋白电泳条带灰度半定量分析结果显示PSD - 95在受伤后1周逐渐减少(P＜0.01). 结论 TBI可致大鼠海马区PSD - 95表达减少,这可能是导致学习、记忆障碍的机制之一.     

大鼠创伤性脑损伤后脑组织钙周期素结合蛋白的表达及意义

目的 探讨大鼠创伤性脑损伤(traumatic brain injury,TBI)后脑组织中钙周期素结合蛋白(calcyclin binding protein,CacyBP)的表达规律及意义.方法 雄性SD大鼠60只,按随机数字表法分为正常对照组(10只)和TBI组(50只);采用头颅侧向旋转致伤方法制作TBI模型,并按伤后大鼠处死时间分为6,24,72 h、7,14 d共5个亚组,每组10只.采用免疫组化方法检测CacyBP在大鼠脑组织中的表达变化规律和分布情况.CacyBP阳性结果判断标准以细胞浆内出现棕黄染色颗粒为阳性,反之为阴性.结果 大鼠脑组织中CacyBP主要分布在海马、齿状回及皮层下神经元的胞浆中.与正常对照组的CacyBP高表达比较.TBI后6 h,其表达量明显减少,为最低值(P<0.01),随后表达量逐渐递增,至损伤后14 d其表达量恢复高值,与正常对照组比较,差异无统计学意义(P>0.05).结论 在TBI后,CacyBP出现一个表达低峰,提示在不同机制影响下其可能对脑损伤的发生、发展发挥重要作用.

Abstract：

Objective To investigate the expression and significance of calcyclin binding protein (CacyBP)in the brain of rat model of traumatic brain injury(TBI).Methods Sixty 60 male SD rats were divided randomly into normal control group (n=10) and TBI group (n=50).The TBI model was created by using lateral head rotation device and subdivided into 6 h,24 h,72 h,7 d and 14 d group (10 rats per group).The expression and distribution of CacyBP in the rat brain was investigated immunohistochemically.The presence of the brown stained particles was considered as"positive"and lack of the stained particles ag"negative". Results CacyBP was mainly distributed in the hippocampus,dentate gyrus and cortical neuron cytoplasm.Compared with the high level expression of CacyBP in the normal control group,the expression of CacyBP was decreased to the lowest in the rat brain at 6 h post TBI (P<0.01),became stronger gradually at 24 hours and recovered to normal at day 14,with no statistical difference compared with normal control group (P>0.05). Conclusion The lowest level expression of CacyBP after TBI indicates that CacyBP may play an important role in development of brain injury under effect of difierent mechanisms.     

促红细胞生成素及其受体在大鼠创伤性颅脑损伤模型中的表达及意义

目的 研究创伤性颅脑损伤(TBI)大鼠损伤周围脑组织促红细胞生成素(erythropoietin,EPO)及其受体(erythropoietin receptor,EPOR)的表达.方法 78只SD大鼠按随机数字表法分为对照组(6只)、假手术组(36只)、液压冲击脑创伤模型组(36只).根据处死时间,分为6,24 h和3,5,7,14 d6个时相点,每个时相点假手术组和脑损伤组各处死6只大鼠,取损伤周围脑组织.利用实时荧光定量PCR和Western blot方法检测EPO、EPOR的mRNA表达和蛋白表达.结果 EPO在伤后24 h内即升高,到第3天达到高峰,并可维持2 d左右,至伤后第7天开始下降,于伤后14 d基本恢复至伤前水平;而EPOR于伤后24 h到达高峰,至伤后14 d表达量仍可维持较高的水平.结论 TBI后24 h内源性EPO及其受体的表达即开始增加,但二者的表达具有不一致性,且EPO相对受体表达具有短暂性.

Abstract：

Objective To study the expressions of erythmpoietin(EPO)and its receptors(EPOR)in the injured brain tissue ofthe rats with traumatic brain injury(TBI).Methods A total of78 SD rats were randomly divided into three groups including control group(six rats),sham group(36rats) and fluid percussion injury group(36 rats).The rats were sacrificed at 6,24 hours,3,5,7 and 14days after TBI in the sham group and the fluid percussion injury group(six rats at each time point).Then,the injured brain tissues were removed for observation of the mRNA and protein expressions of EPO and EPOR by meaDiB of real-time PCR and Western blot. Results The expression of EPO was increased at 24 hours and reached the peak at day 3 after TBI.The hish expression level of EPO could maintain for two days or so.began to decrease at day 7 and recovered to normal at day 14 after Till.While the expression of EPOR reached the peak at 24 hours after TBI and maintained hish level at day14. Conclusions The expressions of EPO and EPOR show increase within 24 hours after TBI.In fact,the expressions of both factors are not in consistency,with more transient expression of EPO.     

脑创伤程度对大鼠伤后胚胎神经干细胞移植的影响

目的 探讨不同程度创伤性脑损伤(traumatic brain injury,TBI)对伤后胚胎神经干细胞(neural stem cells,NSCs)移植的影响. 方法 从孕12～ 14 d胚胎大鼠海马组织中分离NSCs,采用无血清培养法,进行体外培养、扩增和鉴定.大鼠分别于轻型、中型TBI后3d行胚胎NSCs双侧海马区移植;细胞移植14 d后行组织学和TUNEL检测,并对BrdU、NSE、GFAP、GalC、NGF、BDNF蛋白行免疫组化检测. 结果 移植治疗后14 d,轻型TBI组双侧海马区Brdu阳性细胞数明显多于中型TBI组.移植胚胎NSCs脑内分化以GFAP阳性胶质细胞为主.轻、中型TBI后NGF和BDNF蛋白阳性表达增加,其中以轻型TBI组表达最为显著. 结论 轻型和中型TBI对NSCs移植的影响与伤后脑组织局部微环境因素的改变密切相关.     

灯盏花素对创伤性脑损伤大鼠学习记忆功能的影响

目的 观察灯盏花素对创伤性脑损伤大鼠学习记忆功能和脑氧自由基的影响.方法 通过液压损伤法建立大鼠创伤性脑损伤模型,水迷宫实验和避暗实验测定大鼠学习记忆功能,并于测试后取脑测定总超氧化物歧化酶（T-SOD）、丙二醛（MDA）含量.结果 在Morris水迷宫实验中,灯盏花素能明显缩短脑创伤大鼠逃避潜伏期;在避暗实验中,灯盏花素能显著延长脑创伤大鼠学习记忆潜伏期,减少错误次数.灯盏花素可以显著降低脑创伤大鼠脑组织MDA含量和显著增加T-SOD含量.结论 灯盏花素可改善脑创伤大鼠学习记忆功能,其作用与抑制氧自由基反应有关.     

外源性 bFGF对大鼠创伤性脑损伤后学习记忆功能障碍的治疗作用

目的：探讨外源性碱性成纤维生长因子（bFGF)对脑创伤后学习记忆功能障碍的治疗作用。方法：以Mmarmarou's方法制作大鼠重型弥漫性脑创伤模型；利用HE染色，原位细胞凋亡检测及Morris水迷宫技术，对大鼠伤后海马区神经细胞的病理改变及空间学习记忆功能的变化进行动态观察。结果：伤后给予外源性bFGF可明显抑制大鼠海马CA2－3区神经细胞的坏死，凋亡过程，治疗组Morris水迷宫测试潜伏期于伤后第8天及第10天较创伤组明显缩短。结论：海马是学习记忆形成的重要脑功能结构。外源性bFGF通过抑制伤后海马神经细胞缺失，可使大鼠的空间学习记忆功能功能障碍得到明显改善。     

An experimental study of radiation-induced cognitive dysfunction in an adult rat model

The objectives of this study were to establish an adult rat model for the late onset of radiation-induced cognitive dysfunction and to compare behavioural dysfunction with histopathological changes. While under anaesthesia, 30 rats (experimental group) were irradiated with a total dose of 40 Gy, given as eight fractions in 24 days. Another 30 rats (control group) underwent sham irradiation. The cognitive functions of all rats were evaluated at 6, 9 and 12 months after irradiation using the Morris water maze and passive avoidance tasks. Histopathological examination of these rats was carried out after the evaluation of cognitive functions was complete. At 6 and 9 months after irradiation there were no significant differences between the control and irradiated groups in passive avoidance and water maze tests. At 12 months after irradiation, the passive avoidance task revealed a deterioration of cognitive function in the experimental group. Histopathological observations revealed no abnormal findings in the irradiated brains at the light microscope level. Late onset cognitive dysfunction following cranial irradiation was observed in an adult rat model. Pathological investigations showed no abnormalities in the irradiated brains. These findings indicate that radiation-induced cognitive dysfunction can precede morphological changes in the brain or that they arise without them. The present model seems useful for elucidating the pathogenesis of radiation-induced cognitive dysfunction and for developing methods for therapy and prophylaxis.     

大鼠急性负压性脑创伤模型的行为学评估

目的　探索大鼠急性负压性脑创伤模型的行为学特征。　方法　利用负压性脑创伤模型装置制作SD大鼠负压性脑创伤模型。设立负压伤组 (12只 )和假手术对照组 (12只 )。另取 2只负压伤大鼠 1周后处死做HE染色,以观察组织病理变化。以mNSS方法和水迷宫试验对两组大鼠在各时间点进行行为学的评价。　结果　本组大鼠负压打击后死亡 1只,存活大鼠成模率为 100%,负压打击部位的皮层和皮层下呈现局灶的挫伤、出血和组织缺失。负压伤组mNSS评分异常持续到受伤后 25d以前,水迷宫试验平均逃避潜伏期异常不超过 3d。　结论　大鼠负压性脑创伤模型主要适用于以受伤后较短时期内 ( <25d)的神经感觉运动和反射功能为主要目的的研究。     

急性低压低氧应激导致大鼠认知功能损伤研究

目的:探讨急性低压低氧暴露对大鼠大脑海马损伤、氧化应激以及对认知功能的影响。方法:36只大鼠随机分为3组:常压常氧组(对照组)、模拟海拔4000 m组(4 km组)、模拟海拔6000 m组(6 km组)。比较各组大鼠Morris水迷宫学习与记忆测试成绩、海马神经元凋亡、海马组织中GSH、MDA含量和CAT、SOD的活力。结果:与对照组比较,急性低压低氧组大鼠Morris水迷宫测试成绩明显降低(P<0.05);急性低压低氧组大鼠海马组织中GSH含量、SOD和CAT活力均明显降低(P<0.05),MDA含量明显增加(P<0.01);急性低压低氧组大鼠海马神经元凋亡率明显高于常氧饲养组(P<0.01),以上改变均随海拔升高而更为明显。结论:急性低压低氧应激导致大鼠氧化应激系统失衡,而氧化应激反应直接导致海马神经元的细胞凋亡,并最终导致大鼠学习与记忆等认知能力的下降。     

环孢霉素A对弥漫性轴索损伤后大鼠神经功能保护的研究

目的　探讨大鼠弥漫性轴索损伤后应用环孢霉素A治疗能否促进大鼠神经功能的恢复。方法　将 2 4只SD大鼠随机均分为正常对照组、损伤对照组和环孢霉素A治疗组 ,制作大鼠弥漫性轴索损伤模型 ,用Morris水迷宫和木梁平衡实验评价大鼠学习记忆能力和综合平衡能力。结果　环孢霉素A治疗后 ,大鼠在木梁上的时间长于损伤对照组 (F =2 75 4 4 ,P <0 0 1 ) ,在连测的 5天内 ,治疗组和损伤对照组行为评分呈下降趋势 ,治疗组平衡能力好于对照组 (F =36 97,P <0 0 1 )。在水迷宫实验中 ,尽管治疗组找到平台的时间和正常对照组相比有所延长 (F=6 9 2 7,P <0 0 1 ) ,但明显少于损伤对照组 (F =1 72 1 0 ,P <0 0 1 )。结论　环孢霉素A能改善大鼠的学习记忆能力和综合平衡能力 ,促进大鼠神经功能的恢复     

海马区c-fos基因表达在大鼠脑创伤后认知功能障碍中的作用

目的 探讨大鼠脑创伤后海马区c-fos基因表达及对学习记忆功能的影响.方法 建立Marmarou大鼠脑创伤模型,采用分子原位杂交技术和Morris水迷宫分别观察大鼠伤后海马区c-fos基因表达变化及空间学习记忆能力的改变. 结果 伤后30 min海马区神经元即出现c-fos mRNA的表达,1～3 h达高峰,伤后24 h表达基本消失;Morris水迷宫实验,大鼠伤后存在空间学习记忆功能障碍.结论 脑创伤可引起c-fos基因在海马区的表达上调,通过介导延迟性神经元细胞死亡,影响细胞间的信息传递,参与认知功能的损害.     

慢性强迫游泳运动对大鼠放射性认知功能障碍的影响及其机制

目的 探讨慢性强迫游泳运动对大鼠放射性认知功能障碍是否有改善作用及其相关机制。方法 将39只1月龄SD大鼠按随机数字表法分成对照组（C）、对照游泳组（C-S）、照射组（R）和照射游泳组（R-S）。照射组给予单次20 Gy全脑照射,游泳组进行15 min/d,5 d/周的强迫游泳运动。照射后第3个月依次进行自发活动、Morris水迷宫（定向航行、空间探索）行为学检测,完成后取大鼠海马组织,用Western blot方法测定各组大鼠海马中脑源性神经营养因子（BDNF）、磷酸化细胞外调节蛋白激酶（P-ERK）、总细胞外调节蛋白激酶（T-ERK）、磷酸化的环磷腺苷效应元件结合蛋白（P-CREB）和总环磷腺苷效应元件结合蛋白（T-CREB）的分子水平。结果 Morris水迷宫定向航行实验中,对照游泳组第2天平均潜伏期低于对照组,对照组及照射游泳组第2天平均潜伏期低于照射组（P<0.05）。自发活动、Morris水迷宫空间探索实验各组之间差异无统计学意义（P>0.05）。Western blot检测,与对照组比较,电离辐射显著降低了BDNF及其下游信号分子P-ERK和P-CREB的表达（P<0.05）,但是强迫游泳运动改善了这种情形,显著提高了照射组BDNF及其下游信号分子P-ERK和P-CREB的表达（P<0.05）。结论 慢性强迫游泳运动可改善大鼠放射性认知功能障碍,其机制可能是促进海马内BDNF及其下游信号分子P-ERK和P-CREB的表达。     

α-硫辛酸对糖尿病大鼠认知能力的影响

目的检测α-硫辛酸对糖尿病大鼠认知能力的影响情况,探讨α-硫辛酸对糖尿病大鼠学习与记忆影响的机制。方法Wistar大鼠共30只,随机分成3组,对照组10只,治疗组10只,糖尿病组10只。糖尿病大鼠模型用链佐菌素（STZ）制模。12周后,Morris水迷宫测试其学习记忆能力,western blotting检测各组NF—kB蛋白水平表达,TUNEL法检测大鼠海马神经元凋亡情况。结果糖尿病组大鼠学习成绩降低（P〈0．05）,TUNEL阳性细胞增多（P〈0．05）,NF-kB蛋白水平表达增加（P〈0．05）,甜硫辛酸治疗组大鼠较糖尿病组学习成绩升高（P〈0．05）,TUNEL阳性细胞减少（P〈0．05）,NF-kB蛋白水平表达减少（P〈0．05）。结论NF-kB蛋白的表达增高可能与糖尿病大鼠海马神经元凋亡及认知功能障碍有关。α-硫辛酸可能通过降低NF-kB的表达,从而对糖尿病大鼠学习与记忆障碍有一定程度的改善。     

清醒小鼠严重颅脑闭合性撞击伤后大脑皮质和肝脏糖皮质激素受体蛋白表达变化的差异

目的 研究小鼠闭合性严重颅脑外伤后大脑皮质糖皮质激素受体(glucocorticoid receptors,GR)蛋白水平的变化与外周肝脏GR蛋白水平的变化、血清皮质醇、促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)变化的关系.方法 利用BIM-Ⅲ型小型多功能动物撞击机对小鼠清醒致伤,于致伤后30 min、2 h、8 h、24h、48 h、72 h采用Western blot免疫印迹法检测大脑皮质和肝脏GR的蛋白水平的变化,ELISA法检测各组外周血清中ACTH含量,放免法检测皮质醇含量.结果 致伤后2 h大脑皮质和肝脏GR均出现蛋白水平表达降低,8 h后呈现恢复趋势,肝脏GR至72 h仍未完全正常;而大脑皮质GR从致伤后24 h再次呈现持续的表达降低.外周血中ACTH、皮质醇较对照组有明显升高,均具有的两个峰值特征,但是两者的高峰期并不完全吻合.结论 严重颅脑外伤后中枢和外周组织均存在糖皮质激素抵抗,两者的变化具有时相差异性.

Abstract：

Objective To study the relationship of expression of central cortex glucocorticoid receptor (GR) at protein level with GR expression in the liver at protein level and with changes of serum cortisol and adrenocorticotropic hormone (ACTH) following severe closed traumatic brain injury (TBI) in mice. Methods Severe TBI was established in awake mice by using a BIM-Ⅲ biomechanical machine. At 0.5, 2, 8, 24, 48 and 72 hours after TBI, the total cytosolic GR in the cortex and liver were detected with Western blotting. Levels of serum ACTH and cortisol were measured by ELISA technique and radio-immunological assay (RIA) respectively. Results The expression of GR both in the cortex and liver were obviously down-regulated at protein levels at 2-72 hours after TBI and increased slowly eight hours after injury. The GR in the liver showed no recovery at 72 hours after injury and that in the cortex was decreased continually at 24 hours after injury. Serum ACTH and cortisol levels were increased markedly compared with control group, when there were two different peaks in the observation curve.Conclusion There is glucocorticoid resistance both in the central and peripheral tissues after severe closed TBI in the awake mice, which changes in a time-dependent manner.