大鼠脊髓损伤后NGF及其受体TrkA在运动神经元及神经胶质细胞表达的变化

为探讨脊髓损伤后运动神经元及神经胶质细胞内神经生长因子(NGF)及其高亲和力受体(TrkA)表达的变化,用改良Allen重击法损伤SCI组动物T12脊髓,按伤后存活时间再将动物分为脊髓损1 d组、2 d组和5 d组。各组动物的脊髓切片经ABC法免疫组织化学染色,用光镜观察TrkA及NGF在脊髓前角运动神经元表达的变化和胶质纤维酸性蛋白(GFAP)及NGF免疫反应阳性胶质细胞的反应性增生程度,并进行图像分析。结果显示:脊髓损伤后前角运动神经元TrkA及NGF的表达随脊髓损伤后动物存活时间的延长逐渐上调;脊髓白质和灰质内尤其是皮质脊髓束内GFAP及NGF阳性胶质细胞明显增生;与此同时,室管膜细胞内亦可见明显的NGF免疫反应产物。上述结果表明,脊髓损伤可刺激脊髓前角运动神经元表达TrkA及NGF,通过自分泌维持受损神经元的存活;损伤部位反应性增生的胶质细胞亦可产生NGF,通过旁分泌作用于脊髓前角运动神经元或皮质脊髓束的轴突末梢,以维持运动神经元的存活及促进皮质脊髓束的再生;适时补充外源性神经营养素或改变损伤局部的微环境将有利于受损脊髓的修复和再生。     

Morphofunctional characteristics of neurons in the spinal ganglia of the dog in the post-distraction period

The aims of the present work were to study the morphofunctional state of neurons in the spinal ganglia and to perform a comparative analysis of changes in neuron-glial relationships after lengthening of the hindlimb of mongrel dogs by 14–16% of initial at different rates. Longitudinal serial sections of thickness 5 μm of the L6, L7, and S1 ganglia (n = 36) stained with thionine and cresyl violet by the Nissl method and hallocyanine and chromic alum by the Einarson method were examined. Reversible transformations of the structure of some neurons were seen at 45–48 days, these consisting of hyperchromia of the cytoplasm and nucleus, peripheral chromatolysis, displacement of the nucleolus, and increases in the quantities of perineuronal and interneuronal gliocytes. Changes were most marked in the ganglia on the side of limb lengthening at a rate of 3 mm/day, while the smallest changes were seen on the side contralateral to limb lengthening at a rate of 1 mm/day. __________ Translated from Morfologiya, Vol. 127, No. 2, pp. 44–47, March–April, 2005.     

人视网膜胶质细胞的原代培养与鉴定方法

背景 人视网膜胶质细胞在视网膜增生性疾病的研究中有重要作用,以往研究者已成功地培养了人视网膜胶质细胞,但方法学有待进一步改进以达到细胞收获量更大的目的. 目的 建立快速、收获量大且纯度高的视网膜胶质细胞的培养方法,对目标细胞的抗原表达特点进行分析. 方法 取正常人角膜移植供体眼球分离视网膜组织,采用质量分数2％胰蛋白酶和质量分数0.133％胶原酶Ⅵ用二步法消化获取人视网膜胶质细胞,用含质量分数10％胎牛血清的人内皮细胞培养液,其中添加内皮细胞生长因子(β-ECGF)和肝素钠,对分离的细胞进行体外培养,培养皿用纤维黏连蛋白(FN)包被以促进人视网膜胶质细胞贴壁.观察收获的目标细胞的形态特征,采用活体显微镜下形态学观察、常规组织学观察法观察目标细胞的生长,同时采用免疫组织化学法检测胶质纤维酸性蛋白(GFAP)、波形蛋白(Vimentin)、神经元特异性烯醇化酶(NSE)、S-100、CD34、Ⅷ因子在细胞中的表达以鉴定目标细胞. 结果 应用胰蛋白酶、胶原酶二步消化法可成功获取人视网膜胶质细胞,原代培养的细胞72 h贴壁,第9～10天细胞达到融合状态呈花瓣状;常规组织学观察显示细胞核呈鲜亮蓝色,细胞质(盘膜)呈淡红色,培养细胞GFAP、Vimentin呈强阳性表达,NSE、S100、CD34、Ⅷ因子相关抗原表达呈阴性反应. 结论 应用胰蛋白酶、胶原蛋白酶消化法以及利用10％胎牛血清的人内皮细胞培养基,添加生长因子和肝素钠,并用FN包被培养皿进行体外培养可达到快速、大量分离和纯化人视网膜胶质细胞的目的,鉴定结果提示培养的目标细胞为人视网膜胶质细胞,其形态与以往报道的有所不同,具体特点尚需进一步研究.     

沙土鼠大脑额叶皮质明,暗胶质细胞的形态观察

利用光镜及电镜技术，对沙土鼠大脑额叶皮质的神经胶质细胞进行光镜和电镜下的结构观察。得出的结论为，神经胶质细胞分为明、暗胶质细胞、明胶质细胞为星形胶质细胞、暗胶质细胞为少突有产质细胞。     

高压氧治疗对大鼠脑外伤软化灶变化的影响

目的观察高压氧(HBO)综合治疗对脑外伤受损脑组织的影响。方法选用雄性大白鼠126只,制成脑外伤模型,待脑软化灶形成后随机分为三组HBO组42只;HBO综合组44只和药物组40只。三组分别治疗3～9个疗程后,观察软化灶的病理组织学变化。结果在治疗6个和9个疗程后,HBO组和HBO综合组总的基本恢复率均明显优于药物对照组(P<0.001)。结论HBO治疗对脑外伤受损脑组织具有促进细胞新生和脑组织修复的良好作用。     

鞘内注射胶质细胞抑制剂对背根神经节压迫大鼠脊髓星形胶质细胞的影响

BACKGROUND： Astrocytes are considered to provide nutritional support in the central nervous system. However, recent studies have confirmed that astrocytes also play an important role in chronic pain.
OBJECTIVE： To investigate the effects of intrathecal injection of fluorocitrate, minocycline or both on astrocyte activation and proliferation in the spinal dorsal horn of compressed dorsal root ganglion in rats.
DESIGN, TIME AND SETTING： The neurology randomized controlled animal study was performed at the Jiangsu Institute of Anesthesia Medicine, from September 2006 to April 2007. MATERIALS： A total of 96 male Sprague Dawley rats, aged 6-8 weeks, were selected for this study. Following intrathecal catheterization, 80 rats underwent steel bar insertion into the L4-5 intervertebral foramina to make a stable compression on the L4-5 posterior root ganglion. Thus rat models of ganglion compression were established. Minocycline and fluorocitrate were purchased from Sigma, USA.
METHODS： A total of 96 rats were randomly and equally divided into six groups. Rat L4, L5 transverse process and intervertebral foramina were exposed in the sham operation group, but without steel bar insertion. The model group did not receive any manipulations. Rats in the phosphate buffered saline （PBS） group were intrathecally injected with 0.01 mmol/L PBS （20 μL）. Rats in the fluorocitrate group were subjected to 1 μmol/L fluorocitrate （20 μL）. Rats in the minocycline group were intrathecally injected with 5 g/L minocycline （20 μL）. Rats in the minocycline and fluorocitrate group received a mixture （20 μL） of 5 g/L minocycline and 1 μmol/L fluorocitrate. Following model establishment, drugs were administered once a day.
MAIN OUTCOME MEASURES： At 7 and 14 days following model induction, glial fibrillary acidic protein expression in the spinal dorsal horn was measured by immunofluorescence microscopy. Six sections with significant glial fibrillary acidic protein -positive expression were obtained to count astrocytes under an inverted microscope.
RESULTS： No significant differences in astrocyte count were detected between the fluorocitrate and model groups. Cell bodies were small with a few processes in the fluorocitrate group, compared with the model group. The astrocyte count decreased significantly in the minocycline group and the minocycline and fluorocitrate group compared with the sham operation, model, PBS and fluorocitrate groups （P 〈 0.01）. The decrease in astrocyte count was mainly found in layers Ⅲ–Ⅳ of the spinal dorsal horn. Cell body volume was smaller and process numbers were fewer in the minocycline group and the minocycline and fluorocitrate group, compared with the model and PBS groups.
CONCLUSION： Fluorocitrate can inhibit astrocyte activation, but does not affect astrocyte proliferation. However, minocycline can inhibit the activation and proliferation of astrocytes.     

Correlation of iron deposition and change of gliocyte metabolism in the basal ganglia region evaluated using magnetic resonance imaging techniques: an in vivo study

Introduction

We assessed the correlation between iron deposition and the change of gliocyte metabolism in healthy subjects’ basal ganglia region, by using 3D-enhanced susceptibility weighted angiography (ESWAN) and proton magnetic resonance spectroscopy (¹H-MRS).

Material and methods

Seventy-seven healthy volunteers (39 female and 38 male subjects; age range: 24–82 years old) were enrolled in the experiment including ESWAN and proton MRS sequences, consent for which was provided by themselves or their guardians. For each subject, the mean phase value gained by ESWAN was used to evaluate the iron deposition; choline/creatine (Cho/Cr) and mI/Cr ratios gained by ¹H-MRS were used to evaluate gliocyte metabolism in the basal ganglia region of both sides. The paired t test was used to test the difference between the two sides of the basal ganglia region. Linear regression was performed to evaluate the relation between mean phase value and age. Pearson''s correlation coefficient was calculated to analyze the relationship between the result of ESWAN and ¹H-MRS.

Results

There was no difference between the two sides of the basal ganglia region in the mean phase value and Cho/Cr. But in mI/Cr the mean phase value of each nucleus in bilateral basal ganglia decreased with increasing age. There are 16 r-values between the mean phase value and Cho/Cr and mI/Cr in bilateral basal ganglia region. And each of all p-values is less than 0.001 (p < 0.001).

Conclusions

Iron deposition in the bilateral basal ganglia is associated with the change of gliocyte metabolism with increasing age. Iron deposition in each nucleus of the basal ganglia region changes with age.     

癫(癎)发病机制研究进展

癫的发作与大脑神经元异常同步放电有关,是影响人类健康的一大类疾患。本文综合国内外最新研究进展,从离子通道、神经递质受体、突触重塑、神经胶质细胞及皮质发育多方面探讨癫发病机制,以期对癫的形成有进一步认识。