即早基因c-fos在视神经损伤大鼠外侧膝状体中的表达

目的研究大鼠视神经钳夹伤后外侧膝状体神经元的早期损伤反应。方法用70g压力的显微无创血管钳夹持SD雄性大鼠右侧视神经30s,于损伤后2h、1d、3d、7d、14d,采用c-fos和calbindin D-28k抗体行免疫组化和荧光双标检测外侧膝状体中的c-fos定位,用Western印迹法检测外侧膝状体中的c-fos表达量。结果在损伤眼同侧的外侧膝状体腹侧核内侧核团和中间核可见c-fos阳性细胞,损伤后2h开始出现,1d时达到高峰,3d时稍有减少,7d时明显减少,14d仍有少量c-fos阳性细胞。外侧膝状体的背侧核及对照组未见c-fos阳性细胞。Calbindin D-28k阳性细胞主要出现在外侧膝状体的腹侧核内侧核团和中间核内。75％-83％的c-fos都出现在calbindin D-28k阳性细胞的胞核中。结论大鼠的视神经钳夹伤诱导了即早基因c-fos在同侧外侧膝状体腹侧核内侧核团和中间核calbindin D-28k阳性投射神经元中的表达,它们可能在视神经急性损伤的病理过程中起重要作用。（中华眼科杂志,2005,41：321-324）     

补肾活血中药对大鼠慢性高眼压模型外侧膝状体病理改变的影响

目的观察补肾活血中药对大鼠慢性高眼压(elevated intraocular pressure,EIOP)模型外侧膝状体损伤的干预作用,探讨其作用机理。方法采用烙闭上巩膜静脉法建立大鼠慢性EIOP模型,随机分为3组:空白组、模型组、给药组,观察补肾活血中药对EIOP大鼠眼压、外侧膝状体(lateral geniculate nucleus,LGN)病理形态学变化的影响。结果本实验采用的烙闭上巩膜静脉的造模方法使大鼠眼压明显升高,与造模前比较差异有显著统计学意义(P<0.01),在造模后8周(实验结束)眼压仍为造模前的2.5～3.0倍;LGN病理切片半定量分析表明:模型组神经元细胞密度(51.14±10.52)μm-2、神经元剖面积密度(6.57±1.59)μm-2、有髓纤维密度(0.3556±0.1019)μm-2、Nissl小体积分光密度31826±3796,与空白组比较差异均有统计学意义(P<0.01或0.05)。模型组Nissl小体积分光密度低于给药组(33906±3213),给药组神经元细胞密度(54.27±12.70)μm-2与空白组(60.95±13.35)μm-2比较差异有显著统计学意义(P<0.01),给药组有髓纤维密度(0.5611±0.1385)μm-2与模型组比较,差异有统计学意义(P<0.05)。结论补肾活血中药有助于EIOP大鼠LGN损伤的修复。     

大鼠视神经钳伤后外侧膝状体细胞损伤的研究

目的　探讨大鼠视神经钳伤后 ,外侧膝状体 (lateralgeniculatebody,LGB)细胞的损伤情况。方法　用 4 0g视神经损伤钳 ,压迫Sprague Dawley(SD)大鼠双侧视神经 30s,制成视神经部分定量损伤的动物模型。对LGB连续梯度切片 ,7d后用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法 (teriminaldeoxynucleotidyltransferase mediateddUTPnickend labeling ,TUNEL)对LGB细胞进行凋亡检测。 1个月后通过免疫组化染色技术 ,用兔抗鼠神经丝 (neurofilament,NF)单克隆抗体对LGB的神经元进行检测。同时经视觉中枢注入荧光染料颗粒蓝 ,对LGB细胞进行逆行荧光标记 ,在 70 0nm波长荧光显微镜下对连续切片的LGB标记细胞进行平均密度计数 ,并与对照组比较。结果　TUNEL法染色证实LGB细胞发生凋亡。对照组神经丝免疫组化染色呈清晰的条索状 ,而实验组明显减少。对照组LGB细胞密度均值为 (5 172± 2 4 8)个 /mm2 ,而损伤组LGB细胞密度均值为 (414 4± 6 1)个 /mm2 ,两组比较差异有非常显著意义 (t=8 995 ,P <0 0 1)。结论　在大鼠视神经钳伤后 ,LGB细胞受损 ,其损伤机制与凋亡有关     

补肾活血中药对大鼠慢性高眼压模型外侧膝状体脑源性神经营养因子表达的影响

目的 观察补肾活血中药对大鼠慢性高眼压( elevated intraocularpressure,EIOP)模型外侧膝状体(lateral geniculate nu-cleus,LGN)脑源性神经营养因子(brain-derived neurotrophin factor,BDNF)的干预作用,探讨其作用机理.方法 采用烙闭上巩膜静脉法,烙闭SD大鼠3支上巩膜静脉,建立大鼠慢性EIOP模型,将30只(30眼)大鼠随机分为空白组、模型组、给药组,每组各10只.连续灌胃8周,并于8周末处死大鼠,观察补肾活血法对EIOP大鼠眼压及BDNF表达的影响.结果 造模后大鼠眼压均较造模前明显升高(均为P＜0.01),在造模后8周眼压仍为造模前的2～3倍.造模后,模型组造模后即刻、造模后给药组8周眼压分剐为(28.1400±7.391 9)mmHg(1 kPa=7.5 mmHg)、(27.580 0±6.312 9) mmHg,给药组分别为(31.740 0±8.315 3) mmHg、(25.640 0±5.589 4) mmHg,与空白组相比,差异均有统计学意义(均为P＜0.01).LGN病理切片半定量分析表明模模型组BNDF表达总面积(168 614±10 724) μm2、平均光密度( 3066±708)、积分光密度(44 443 ±3721),与空白组的总面积(255 985 ±31 225) μm2、平均光密度(6070±609)、积分光密度(61 174±6226)比较差异均有显著统计学意义(均为P＜0.01).给药组的BDNF表达总面积(211 739±28 336)μm2、积分光密度(55 793±7608).与模型组比较差异均有显著统计学意义(均为P ＜0.01);给药组BDNF表达总面积与空白组比较差异有显著统计学意义(P＜0.01).结论 补肾活血中药有助于增强EIOP大鼠LGN的BDNF表达.     

糖尿病大鼠脑外侧膝状体神经元退行性变及APP17肽的作用

目的 通过观察糖尿病大鼠外侧膝状体神经元超微结构改变和神经元内凋亡相关因子Bax、Bcl-2、Cyto C的表达，证实糖尿病大鼠是否存在脑内视觉传导通路外侧膝状体神经元退行性改变，APP17肽对其是否有改善作用。方法 用链脲佐菌素(STZ)腹腔注射诱发糖尿病模型，10周后取脑组织行Bax、Bcl-2、Cyto C的免疫组化染色，同时取外侧膝状体处脑组织作电镜观察。结果 糖尿病组外侧膝状体腹侧核内Bax、Cyto C阳性反应神经元数目多、染色深，Bcl-2三组间无明显差异，APP17肽治疗组的Bax、Bcl-2、Cyto C的表达接近正常组。超微结构发现糖尿病组神经元有固缩、核膜凹陷、线粒体肿胀等退行性变，给予APP17肽后上述改变明显好转。结论 糖尿病大鼠发生了外侧膝状体神经元的退行性改变，神经元可能处于凋亡前状态；APP17肽可改善糖尿病大鼠外侧膝状体神经元的退行性改变。     

大鼠外侧膝状体神经元时空频率调谐特性发育观察

背景 外侧膝状体(LGN)是视觉通路中重要的视觉信息处理器官,近年来发现LGN参与运动视觉信息处理,功能磁共振成像检查表明在LGN水平存在着双眼竞争,可能与弱视的发生有关.然而,LGN神经元时空频率特性的研究多限于猴或者猫,大鼠的相关研究较少. 目的 观察不同年龄段大鼠LGN神经元感受野时空频率调谐特性.方法 取睁眼后14～16d组、20 ～ 22 d组、27 ～30d组及睁眼后60 d组Wistar 大鼠各5只,用在体细胞外记录技术,通过正弦光栅视觉刺激分别对各组大鼠LGN神经元感受野时空调谐特性进行检测,观察大鼠LGN神经元时空频率调谐特性随着发育发生的动态变化. 结果 睁眼后14～16 d组、20～22 d组、27 ～30 d组及睁眼后60d组大鼠LGN神经元时间和空间频率调谐低通调制和带通调制间神经元数量的差异均无统计学意义(x2=0.68、0.47,P＞0.05),4个组大鼠LGN神经元感受野最优时间频率调谐特性成年后达最高值,大鼠LGN神经元的最优时间频率均值分别为(2.5±1.3)、(2.6±1.2)、(2.6±1.1)、(3.6±1.1)Hz,差异有统计学意义(F=4.53,P＜0.05),睁眼后60d组的最优时间频率明显高于睁眼后14～16 d组、20 ～22 d组、27 ～30 d组,差异均有统计学意义(q=4.43、4.10、4.03,P＜0.05),睁眼后14 ～ 16 d组、20～22 d组、27 ～30 d组间的相互比较差异均无统计学意义(P＞0.05).4个组大鼠LGN神经元的最优空间频率均值分别为(0.04±0.04)、(0.04±0.03)、(0.05±0.03)、(0.05士0.04)cpd,差异均无统计学意义(F=0.58,P＞0.05),而时间频率瞬时带宽及空间频率带宽各年龄组间比较,差异均无统计学意义(F=0.37、1.22,P＞0.05).结论大鼠LGN神经元感受野时空频率调谐发育特性的不同可能与其在视觉通路中的功能有关.     

单眼视功能损害的原发性开角型青光眼患者的外侧膝状体损伤

目的研究单眼晚期视功能损害的原发性开角型青光眼患者外侧膝状体的形态改变情况。方法选取单眼晚期视功能损害的原发性开角型青光眼患者6例(青光眼组)及性别、年龄匹配的正常对照者8例(对照组),均行外侧膝状体的3.0T磁共振成像扫描,测量外侧膝状体的最大高径和体积。比较青光眼组及对照组杯盘比、视网膜神经纤维层(retinalnervefiberlayer,RNFL)厚度、视野平均缺损值及对比分析青光眼组及对照组外侧膝状体各相关指标的统计学差异。结果所有受试者外侧膝状体均可清晰成像。青光眼组右侧外侧膝状体最大高径、体积分别为(4.52±0.57)mm、(104.80±21.10)mm3,左侧为(4.30±0.26)mm、(101.50±27.70)mm3,差异均无统计学意义(t=0.850,P=0.415;t=0.235,P=0.819)。正常对照组右侧外侧膝状体最大高径、体积分别为(5.14±0.35)mm、(136.80±14.40)mm3,左侧为(4.98±0.31)mm、(141.90±16.80)mm3,差异均无统计学意义(t=0.665,P=0.510;t=0.141,P=0.888)。青光眼组双侧外侧膝状体最大高径及体积均较正常对照组减小(均为P<0.05);杯盘比、RNFL厚度差异有显著统计学意义(均为P<0.001),而视野平均缺损值差异无统计学意义(P=0.143)。结论原发性开角型青光眼单眼视功能损害的患者中枢损伤可累及双侧外侧膝状体,二维最大高径及三维体积均明显萎缩,3.0T磁共振成像可以清晰显示这个变化,从影像学角度加深对青光眼中枢损伤的认识。     

单眼剥夺大鼠视皮层及外侧膝状体中生长相关蛋白(GAP-43)的表达及其意义

目的研究生长相关蛋白(GAP-43)在正常大鼠与视觉剥夺性大鼠视皮层及外侧膝状体中的表达情况。方法缝合2周龄大鼠单侧眼睑30天,切取外侧膝状体和视皮质,应用免疫细胞化学SP法技术染色和计算机图像分析GAP-43在正常组和单眼视觉剥夺组大鼠外侧膝状体和视皮层的表达及变化。结果 1．GAP-43在正常大鼠视觉系统的表达主要见于外侧膝状体全层和视皮质Ⅱ-Ⅳ层神经元胞膜中,呈环状或点状棕黄色免疫阳性反应;2．在敏感期内视觉剥夺眼对侧外侧膝状体和视皮质GAP-43表达的免疫阳性神经元染色变淡(P<0．05), 且免疫阳性神经元数目减少(P<0．05)。结论单眼视觉剥夺大鼠外侧膝状体和视皮质GAP-43表达均降低,提示 GAP-43在视觉系统的作用可能是弱视发生的分子生物学基础之一。单眼剥夺性大鼠视觉系统的GAP-43表达降低可能是由于剥夺眼视觉系统神经元在发育敏感期内,长期视觉剥夺效应使其在双眼竞争突触位点时处于劣势, 表达GAP-43的能力降低。     

P物质在单眼剥夺性弱视猫外侧膝状体中的表达

目的检测SP在单眼剥夺弱视猫LGN中的表达,并探讨其在弱视发病中的意义.方法采用免疫组化APA法,对7例正常猫和8例单眼剥夺弱视猫LGNSP免疫阳性神经元及神经纤维进行定位并定量研究其变化.结果在单眼剥夺猫剥夺侧LGN的A1层SP表达显著下降(P＜0.05).结论单眼剥夺可造成剥夺侧LGN剥夺眼相应输入层次的SP表达下降,从而促进弱视的发生发展.     

青光眼患者的颅内段视神经、外侧膝状体及视皮质内的神经变性

青光眼的视网膜和视神经病理研究已很广泛。近年来对猴实验青光眼模型的研究表明,在外侧膝状体（LGN）和视皮质中也存在青光眼性损害。本文首次报告一例原发性开角型青光眼患者颅内视神经、LGN和视皮质内存在的退化性病理改变,且这种改变与患者的视乳头形态、视野及神经放射学改变相符。患者男性,79岁。诊断1年后死于急性病毒性心肌炎。双眼C／D0．9,颞下方盘沿变窄,Humphrey 24—2视野显示上方缺损。尸检病理检查无其他神经系统疾病。4例与之年龄匹配的无眼部和神经性疾病、死于肺部疾病的患者的视神经和其中3例患者的脑组织与本例患者的视神经及脑组织进行对照检查。     

Chronic ocular hypertension induces dendrite pathology in the lateral geniculate nucleus of the brain

In glaucoma, there is atrophy and loss of retinal ganglion cells (RGC), in addition to atrophy and loss of target neurons in the lateral geniculate nucleus (LGN) of the brain. To investigate possible changes to the dendrites of LGN neurons in glaucoma, a selective marker for dendrites called microtubule-associated protein-2 (MAP2) was used. The LGNs from five monkeys with varying degrees of optic nerve fiber loss were compared to those from five normal control monkeys. Dendrites in magno- and parvocellular layers connected to the glaucomatous eye were evaluated. In controls, long MAP2-positive dendrites with multiple fine branches were seen. However, chronic ocular hypertension induced striking disruption of dendrites with a thickened and shortened appearance. Dendrite field area was significantly reduced in the glaucoma group compared to controls. Sholl analysis revealed reduced dendrite complexity by 47% and 41% in magnocellular layer 1 and parvocellular layer 6, respectively in the glaucoma group compared to controls. The striking dendrite changes in the LGN following chronically elevated intraocular pressure may be relevant to early visual dysfunction in glaucoma.     

Changes in visual fields and lateral geniculate nucleus in monkey laser-induced high intraocular pressure model

Monkey eyes are useful for ophthalmologic research into eye diseases because their histological and functional properties are very similar to those of humans. The monkey laser-induced high intraocular pressure (IOP) model is a common model for ophthalmologic research, especially into glaucoma. Although several studies using this model have focused on changes in visual field, retinal ganglion cells (RGC), and lateral geniculate nucleus (LGN), clear relationships among these changes in one and the same monkey have not been established. We therefore examined visual field changes, RGC and LGN numbers, and glial fibrous acidic protein (GFAP) immunohistochemistry in the LGN in each of two monkeys. Visual field sensitivity, RGC number, and neuronal density of LGN were all decreased by high IOP. The relationship between loss of RGC and decrease in visual field sensitivity depended on the eccentricity from the fovea. Moreover, LGN immunohistochemistry revealed greater increases in GFAP expression in the layers receiving a neuronal input from the high IOP eye than in those receiving a neuronal input from the contralateral untreated eye. From these results, we suggest that glaucoma may lead to changes in glial function not only in the retina, but also in the visual pathway, and that such central nervous system changes may be a hallmark of neuropathy in glaucoma, as in other neurodegenerative diseases.     

表没食子儿茶素没食子酸酯对大鼠视神经钳夹伤后外侧膝状体神经元保护作用的研究

背景研究证实绿茶提取物表没食子儿茶素没食子酸酯（EGCG）全身应用可到达视神经及视网膜组织,对视网膜缺血一再灌注和视神经钳夹伤后视网膜神经节细胞（RGCs）具有保护作用,但EGCG对视神经损伤后RGCs上位神经元的影响目前尚未见报道。目的探讨EGCG对大鼠视神经钳夹伤后外侧膝状体（LGN）神经元的保护作用。方法48只Wistar大鼠按随机数字表法分为正常对照组、假手术＋EGCG组、视神经钳夹＋生理盐水组、视神经钳夹＋EGCG组,每组12只。用40g微型视神经夹于大鼠右眼球后约2mm处夹持视神经60S建立视神经钳夹伤模型,假手术＋EGCG组、视神经钳夹＋EGCG组大鼠于造模前2d始每日腹腔内注射EGCG（25mg／kg）共5d,后改为口服（2mg／kg）,视神经钳夹＋生理盐水组大鼠以同样的方法注射生理盐水。于造模4周后处死大鼠并取脑组织,用Nissl染色法计数外侧膝状体背侧核（dLGN）神经元数目,用免疫组织化学染色法和Westernblot法观察神经丝蛋白（NF-L）在LGN的表达,比较各组大鼠dLGN中神经型一氧化氮合酶（nNOS）免疫组织化学染色阳性细胞数量。结果视神经钳夹伤后4周,假手术＋EGCG组左侧、右侧dLGN神经元数量与正常对照组相比差异无统计学意义（P=0．906、P=0．561）;视神经钳夹＋生理盐水组、视神经钳夹＋EGCG组钳夹同侧dLGN神经元数量与正常对照组相比,差异无统计学意义（P=0．794、P=0．646）,对侧dLGN神经元数量均低于正常对照组（P=0．000、P=0．015）,而视神经钳夹＋EGCG组钳夹对侧dLGN神经元数量高于视神经钳夹＋生理盐水组（P=0．007）;NF－L检测可见视神经钳夹＋EGCG组钳夹对侧LGN的NF－L表达量高于视神经钳夹＋生理盐水组（P=0．002）;dLGN的nNOS阳性细胞计数在正常对照组、假手术＋EGCG组、视神经钳夹＋EGCG组之间差异无统计学意义（P〉0．05）,而视神经钳夹＋生理盐水组钳夹对侧dLGN的nNOS阳性细胞高于视神经钳夹＋EGCG组（P=0．000）。结论EGCG对大鼠视神经钳夹伤后LGN的神经元可能具有一定的保护作用,这种保护作用可能与EGCG抑制了nNOS的表达有关。     

Magnetic resonance imaging assessment of the lateral geniculate nucleus volume and height in patients with glaucoma: a Meta-analysis

AIM: To evaluate the lateral geniculate nucleus (LGN) volume and height using magnetic resonance imaging (MRI) in glaucoma patients. METHODS: Literatures retrieval was carried out through PubMed, Web of Science, Embase, and Cochrane Library. Studies that compared the volume and height of LGN in glaucoma patients with that in control subjects were included. The volume and height of LGN were extracted from the included studies. The Review Manager 5.4.1 software was used for the Meta-analysis. RESULTS: This Meta-analysis included 10 cross-sectional studies, including the eyes of 223 glaucoma patients and 185 healthy controls. Compared with the control subjects, the volume and height of LGN in glaucoma patients measured by MRI were significantly reduced {-29.13 mm3, 95% [confidence interval (CI): -44.82 to -13.43, P=0.0003; -0.61 mm, 95%CI: -0.78 to -0.44, P<0.00001, respectively]}. Subgroup analysis demonstrated that the differences of LGN volume and height between glaucoma patients and control subjects in the older group were smaller than that in the younger group, and LGN volume decreased with the increase of glaucoma severity. CONCLUSION: The results demonstrate that the volume and height of LGN are decreased in glaucoma patients, and LGN volume can be considered a parameter of glaucoma severity.     

Echographic measurements of the retrobulbar optic nerve in normal and glaucomatous eyes

AIM—A study was designed to investigate whether measurements of the optic nerve diameter (OND) and cross sectional area (ONCSA), as measured by B-scan ultrasonography, are altered in glaucoma. The reproducibility and test-retest variability of echographic estimates of retrobulbar optic nerve dimensions was also tested.
METHODS—One eye of 49 glaucoma patients and 90 control subjects underwent five repeated echographic measurements of the maximal interpial diameter and cross sectional area of the orbital optic nerve on two separate occasions. All measurements were taken by one experienced ultrasonographer.
RESULTS—Mean optic nerve diameter (SD) for the control group was 2.86 (0.46) mm, and was independent of height (multiple regression analysis: p = 0.21), axial length (p = 0.74), spherical equivalent (p = 0.97), sex (ANOVA: p=0.36), or race (p=0.14), but was inversely related to age (p = 0.01). Reproducibility of OND readings in control subjects was 0.149 mm (coefficient of repeatability). Test-retest variability of interpial diameter was −0.02 (0.29) mm. Mean interpial diameter of the optic nerve was significantly smaller among glaucomatous eyes (2.58 (0.501) mm) than controls (Mann-Whitney U test: p < 0.0001). Glaucomatous optic nerves also had a significantly smaller cross sectional area (6.68 (2.58) mm²) than those of healthy volunteers (8.25 (1.67) mm²) (p = 0.004).
CONCLUSION—Echographic measurements of the orbital optic nerve are highly reproducible and not subject to clinically meaningful test-retest variability. Optic nerve interpial diameter and cross sectional area are reduced in glaucomatous eyes, reflecting nerve fibre loss. This technique may be useful in distinguishing between normal and glaucomatous eyes where optic disc morphometry is inconclusive or impossible as a result of opaque media.

Keywords: glaucoma; optic nerve; ultrasound