嗅茎切断对脑室下层细胞迁移的影响(英文)

Effects of cutting the olfactory peduncle on migration of subventricular zone cells in adult rats

背景:在成年大鼠的脑室下层存在神经元前体细胞,这些细胞持续不断沿着嘴侧迁移流不停地向嗅球迁移并分化嗅球内的中间神经元,阻断嘴侧迁移流对这些细胞的迁移以及分化是否产生影响尚不得而知。目的:探讨嘴侧迁移流阻断对脑室下层细胞迁移的影响。设计:随机对照实验。单位:中国科学技术大学生命科学学院;徐州医学院人体解剖学教研室。材料:实验于1997-09/1999-01在徐州医学院动物实验中心完成,选用成年雄性SD大鼠25只。随机分为嗅茎切断30d组(n=10)和60d组(n=15,其中5只作免疫组织化学)。方法:在嗅球后切断嗅茎,手术30,60d后将动物灌注固定处死,制作脑的连续石蜡切片,计量嗅球后份平面嘴侧迁移流的细胞密度和横截面积、用免疫组织化学的方法对嘴侧迁移流内的细胞进行定性分析。主要观察指标:嗅茎后份平面的细胞密度,横截面积和唾液酸-神经细胞黏附分子的表达。结果:纳入25只SD大鼠,因手术动物死亡和嗅茎切断手术失败,用于分析的动物只有13只,30d组5只,60d组8只(其中用于免疫组织化学的3只)。①嗅茎切断后嗅茎后份平面嘴侧迁移流形态学及数量变化:在Nissl染色的切片上,嘴侧迁移流细胞较密集,染色深,和周围组织区别明显。未见明显的核固缩、核碎片等细胞死亡的特征。嗅茎切断30d组和60d组手术侧嗅茎后份平面的细胞密度均高于对照侧(P<0.01),60d组手术侧嘴侧迁移流在嗅茎后份平面的相对细胞密度高于30d组手术侧的细胞密度(P<0.01)。两组手术侧横截面积均大于对照侧(P<0.01),但嗅茎切断60d组和30d组手术侧无差异(P>0.05)。②嗅茎切断手术后嘴侧迁移流细胞的免疫组织化学反应:嗅茎切断60d后,嗅茎后份平面嘴侧迁移流内积聚的细胞表现为多唾液酸-神经细胞黏附分子阳性。结论:切断嗅茎导致嘴侧迁移流内神经元前体细胞在切断平面的尾侧积聚,这些集聚的细胞可能发生分化。

BACKGROUND：There are neuronal precursors in subventricular zone （SVZ） of adult rat. The precursors migrate to olfactory bulb along the rostral migratory stream （RMS） and differentiate into local interneurons of olfactory bulb. But whether cutting the RMS would affect the migration of subventricular precursors is unknown.OBJECTIVE： To investigate the effects of cutting the olfactory peduncle on migration of subventricular zone cells in adult rat.DESIGN： Randomized controlled experiment.SETTING： College of Life Sciences, Univesity of Science and Technology of China; Staff Room of Anatomy, Xuzhou Medical College MATERIALS： The experiment was conducted in the Animal Experimental Center , Xuzhou Medical College from September 1997 to January 1999.Totally 25 male adult SD rats were recruited and randomly divided into olfactory peduncle-cutting 30 days group （n=10） and olfactory peduncle-cutting 60 days group（n=15, in which 5 rats were used for immonohisto chemistry）.METHODS： 30 days and 60 days after being cutting olfactory peduncle,the rats were put to death by perfusion for fixation. Consecutive paraffin sections of brain were made. Cellular density and cross section area of RMS were measured. Quantitative analysis of cells in the RMS was performed with immunohistochemical method.MAIN OUTCOME MEASURES： The cellular density and cross section area of RMS, the expression of polysialylated neuronal cell adhesion molecule （PSA-NCAM）RESULTS： Totally 25 SD rats were recruited. Died for operation and been failure for cutting the olfactory peduncle, so altogether 13 rats used for analysis, 5 rats in 30days group and 8 rats in 60 days group （among that, 3 used for immunohistochemistry）. ① Morphologyand quantitative change of RMS after cutting olfactory peduncle： The Nissl stained RMS cells were distinguished from adjacent tissue by the characterization of darken stained and dense distribution. There is little condensed nuclear or fragment nuclear. Cellular density at the operation side in the olfactory peduncle -cutting 30 days group and olfactory peduncle -cutting 60 days group was higher than that in the control side （P ＜ 0.01）. Relative cellular density of RMS at surgical plane of operation side in the olfactory peduncle -cutting 60 days group was higher than that in the olfactory peduncle -cutting 30 days group（P ＜ 0.01 ）. The cross section area of operation side in the two groups was both larger than that of the control side （P ＜ 0.01）. There was no difference of cross section area between olfactory peduncle -cutting 60 days group and olfactory peduncle -cutting 30days group （P ＞ 0.05）. ②Immunohistochemical reaction of RMS after cutting alfactory peduncle operation： 60 days after cutting olfactory peduncle, the accumulated cells in RMS were positive to polysialylated neuronal cell adhesion molecule.CONCLUSION： Cutting the olfactory peduncle results in the accumulation of neuronal precursors of RMS and increases the differentiation of migrating neuronal precursors.