老年大鼠下丘脑视上核和弓状核的超微结构变化

观察老年大鼠下丘脑视上核腹侧大细胞神经元和弓状核神经元的超微结构,结果显示:老年大鼠视上核腹侧血管加压素(VP)神经元的胞体较成年鼠大,胞质结构比较致密,内含许多核糖体颗粒,粗面内质网分散成小泡状,神经分泌颗粒增多,溶酶体、线粒体、高尔基氏复合体数量都较多.而弓状核内的暗细胞和亮细胞的核糖体减少,高尔基氏复合体和线粒体都变化,还有少数神经元固缩,细胞质内胞器明显减少,呈现变性现象.结果提示:老年期下丘脑视上核VP神经元机能增强;而弓状核内两种细胞都显示机能减弱的征象.老年时下丘脑各核团神经元的这种不协调性变化,可能是动物衰老的一种重要表现.     

衰老大鼠禁水时视上核加压素能神经元超微结构变化

电镜观察不同禁水时间衰老大鼠下丘脑视上核加压素能神经元的超微结构变化。结果发现：禁水６、１２ｈ后，视上核加压素能神经元胞体增大，胞质中粗面内质网排列紧密且增多，高尔基复合体成熟面未成熟分泌颗粒及神经分泌颗粒增多；轴突中神经分泌颗粒增多不明显。而禁水２４ｈ后，神经元胞质内的神经分泌颗粒减少，轴突中的神经分泌颗粒聚集成膨大区域。禁水后，神经胶质细胞减少，突起回缩，使相邻的两神经元直接接触，突触结构重建增多。上述研究结果提示，衰老大鼠下丘脑视上核加压素能神经元在禁水时，其功能活动是增强的，胶质细胞突起回缩，有利于神经元之间的突触结构重建。     

老年大鼠禁水时室旁核加压素样神经元免疫电镜观察

用免疫细胞化学ＰＡＰ法对禁水老年大鼠室旁核加压素样神经元的超微结构进行了观察研究。结果显示实验老年大鼠室旁核加太素样神经元蛋白质的合成功能活跃，表现为粗面内质网丰富，高尔基复合体发达，胞质内神经分泌颗料增多；随着禁水时间的延长，胞质中神经分泌颗粒渐减少，轴突内神经分泌颗粒增多，并聚集成膨大区域。此外，部分神经元胞体间的细胞间隙变窄，甚至有胞膜并例。此外还对上述结果对禁水时老年大鼠室旁核加压素样神经     

不同禁水时间老龄大鼠下丘脑大细胞分泌神经元的免疫电镜观察

电镜观察了不同禁水时间老龄大鼠下丘脑视上核和室旁核分泌神经元，即加压素和催产素神经元及胶质细胞的超微结构变化，结果显示，禁水6与12h后，上述两核团中的分泌神经元胞体增大，胞质中粗面内质网（RER）排列紧密且规则，高尔基（Golgi)器的未成熟分泌颗粒及神经分泌颗粒增多，轴突内神经分泌颗粒少见，胶质细胞成份减少，突起回缩；相邻两神经元胞膜直接接触，质膜并列现象及突触增多，而在禁水24h后，神经元胞体内的神经分泌颗粒有减少，轴突中的神经分泌颗粒却增多并聚集成膨大区域，以上结果提示老龄大鼠视上核和室旁核的分泌神经元在禁水时其合成激素的功能是活跃的，而且催产素神经元的结构变化与加压素神经元结构变化是相似的，胶质细胞的结构变化为神经元质膜并列及突触的形式提供了有利条件。     

棉酚对大鼠下丘脑超微结构影响的观察

本文观察了棉酚对雄性成年大鼠下丘脑弓状核、视上核和室旁核细胞超微结构的影响。棉酚以每日30mg/kg体重给大鼠灌服,连续5周。结果表明服棉酚后,视上核和室旁核变化不明显;而弓状核中,部分细胞呈现一系列神经分泌功能增强的变化,高尔基复合体和粗面内质网轻度扩张,内充均质低电子密度物质;神经分泌颗粒、溶酶体、核仁样体和微管数量增多。本文并对以上超微结构改变的性质、意义和可能原因进行了讨论。     

大鼠小脑皮质衰老的形态学研究—颗粒细胞及星形胶质细胞的超微？…

本文对青年，成年及老年Ｗｉｓｔａｒ大鼠小脑皮质颗粒细胞豚星形胶质细胞的电镜研究表明：（１）个别老年大鼠颗粒细胞出现了如线粒体肿胀，基质密度异常，粗面内质网扩张等衰老形态学变化，但老年组大部分颗粒细胞未出现明显的形态学改变；（２）星形胶质细胞中脂褐素在成年组大鼠中即大量出现，且结构复杂，而老年组大鼠胶质细胞中脂褐素含量反而有所下降；此外，老年组星形胶质组织胞质肥大，微丝增多，且胞质内空泡变性，髓样结     

大鼠小脑皮质衰老的形态学研究──颗粒细胞及星形胶质细胞的超微结构变化

本文对青年、成年及老年Wistar大鼠小脑皮质颗粒细胞及星形胶质细胞的电镜研究表明：（1）个别老年大鼠颗粒细胞出现了如线粒体肿胀、基质密度异常，粗面内质网扩张等衰老形态学变化，但老年组大部分颗粒细胞来出现明显的形态学改变；（2）星形胶质细胞中脂褐素在成年组大鼠中即大量出现，且结构复杂，而老年组大鼠胶质细胞中脂褐素含量反而有所下降；此外，老年组星形胶质细胞胞质肥大，微丝增多，且胞质内空泡变性、髓样结构及小泡等内含物增加。     

巢蛋白在成年大鼠室周器官细胞的表达

目的:观察巢蛋白在成年大鼠室周器官细胞的表达,并根据巢蛋白阳性表达细胞的位置、大小及形态特点进行分类.方法:成年SD雄性大鼠,经心灌注后,用免疫组织化学检测巢蛋白在室周器官细胞的表达.结果:在正中隆起(64.32％±8.55％)、穹隆下器(15.76％±2.16％)、连合下器(40.15％±6.16％)和最后区(28.85％±4.53％)都可见大量的巢蛋白阳性表达细胞.根据细胞所在位置、大小和形态将其分为5类.Ⅰ类是室管膜细胞,部分室管膜细胞有长10～180 μm的胞突;Ⅱ类细胞较小,细胞及细胞核呈圆形或卵圆形,有1～2个纤细长达20～30 μm的胞突;Ⅲ类细胞胞体较Ⅱ类大,细胞及细胞核不规则,胞质浅染,无胞突;Ⅳ类细胞及细胞核呈圆形或卵圆形,大部分细胞无胞突,部分细胞有长4～15 μm的胞突;Ⅴ类细胞胞体较大,细胞及细胞核呈圆形或卵圆形,有1～3个粗长的突起,并可见2～3级分支,胞突长50～100μm.结论:成年大鼠室周器官有大量巢蛋白阳性表达细胞,有的是具有增殖和分化潜能的神经干细胞/祖细胞,有的是巢蛋白阳性表达的神经元.     

D-半乳糖衰老大鼠性腺轴系超微结构的变化

目的:观察D-半乳糖衰老大鼠性腺轴系超微结构的变化。方法:D-半乳糖连续腹腔注射制作亚急性衰老的大鼠模型,应用透射电镜观察模型大鼠下丘脑弓状核、垂体及睾丸超微结构的变化。结果:D-半乳糖衰老大鼠弓状核出现线粒体嵴断裂、粗面内质网脱颗粒、高尔基复合体扩张等变化;垂体促性腺激素细胞出现线粒体嵴断裂、粗面内质网扩张、高尔基复合体扩张等变化,并观察到脱粒细胞;睾丸支持细胞内溶酶体增多,内质网增生、扩张,线粒体嵴断裂,精原细胞可见胞质内出现许多空泡,并观察到了凋亡小体。结论:D-半乳糖衰老大鼠性腺轴系的超微结构发生了明显改变,揭示了D-半乳糖衰老过程中下丘脑垂体性腺轴的重要作用。     

棉酚对大鼠下丘脑视上核、室旁核和弓状核影响的组织学和组织化学观察

本文应用组织学和组织化学方法,观察了喂饲棉酚(30mg/kg/d×5周及30 mg/kg/d×5周+60mg/kg/周×5周)的成年雄性大鼠下丘脑视上核、室旁核和弓状核神经元的一般形态结构,以及反映神经分泌功能的形态学指标。结果表明,饲药5及10周,上述三个核团神经分泌细胞的光镜形态学,未见明显变化;根据细胞核体积测量、尼氏体和神经分泌物质含量,硫胺素焦磷酸酶和酸性磷酸酶活性的半定量测定,三核团神经分泌活性无显著改变,仅用药5周时,室旁核尼氏体含量增加。这说明抗生育有效剂量棉酚,对大鼠下丘脑没有明显的直接作用;室旁核分泌活性一度增强,可能是大细胞性神经分泌系统,对棉酚引起机体内环境某些改变的生理性调节反应。     

The influence of age on the response of the supraoptic nucleus of the hypothalamo-neurohypophyseal system to physiological stress II. Quantitative morphology

A quantitative study of various morphological parameters of neuroendocrine cells from the hypothalamo-neurohypophyseal system has been carried out. The cells of the supraoptic nucleus (SON) of male C57BL/ICrfa^t mice at 6 and 28 months of age were examined from both normally hydrated and osmotically loaded animals. The only significant age-related difference between the principal components of the SON (i.e. SON cells, glia, capillary and neuropil) from normally hydrated mice was an increase in the relative volume fraction of the capillary lumen in the SON of old animals. No significant differences could be detected in the above-mentioned components of the SON from young and old salt-stressed mice.There were differences relating to age and to salt stress in the volume fractions of several sub-cellular components of SON cells. Under the influence of osmotic stress there was an increase in the relative volume of the SON cell occupied by cytoplasm when compared to the controls; the response was similar at both ages tested. Similarly for the nucleus, the relative volume of the SON cell occupied at both ages in control and salt-stressed animals was of the same order. The relative volume of SON cells occupied by mitochondria did not alter at either age during salt stress; however, the number of mitochondria per unit area of SON cell cytoplasm fell significantly in the old salt-stressed mice. The volumes of the Golgi and the hormone-containing granules (neurosecretory granules) of these cells remained the same with both age and salt stress. The surface area of the rough endoplasmic reticulum, however, was similar in SON cells from old and young controls, but there was significantly less rough endoplasmic reticulum in cells from the old when compared with the young salt-stressed animals. There was a significant increase in the volume of the soncell occupied by lipofuscinnin old animals, and the relative volume of age pigment was significantly reduced in the cells of salt-stressed animals at both ages.The morphological correlates of functional activity in the SON cells from young, osmotically loaded mice are similar to those seen in other laboratory rodents under the same conditions. In the old animal, the overall response to osmotic stress by the SON as an organ, and also by the individual cells (i.e. cytoplasm and nucleus), are similar to those in young animals. However, there are significant differences in detail, particularly with respect to mitochondrial numbers, surface area of rough endoplasmic reticulum and the relative volumes of lipofuscin and “lipid bodies” in these cells. The morphological correlates of hormone production (neurosecretory granules) do not show age-related changes. The findings are discussed with respect to the efficiency of function of the aged neuroendocrine cell under osmotic stress conditions.     

大鼠下丘脑催产素样和加压素样神经元与5-羟色胺及儿茶酚胺能传入纤维末梢的关系

用免疫组织化学ABC双标记法,显示下丘脑各神经分泌核区中催产素样免疫反应(oxytocin-like immunoreactivity,OT-li)、加压素样免疫反应(vasopressin-like immunoreaetivity,VP-li神经元及5-羟色胺样免疫反应(serotonin-like immunoreactivity,5-HT-li)和儿茶酚胺能,即酪胺酸羟化酶免疫反应(tyrosine hydroxylase-like immunoractivity,TH-li)纤维末梢,对这两种单胺能纤维末梢在视上核、室旁核及各种神经分泌副核中的分布,及其与OT-li和VP-li神经元相关的特点及异同加以分析。结果显示,5-HT-li与TH-li纤维末梢在下丘脑视上核、室旁核及各神经分泌副核中,与OT-li及VP-li神经元相接触的多寡程度多不相同。视上核、室旁核内有极高密度的TH-li纤维末梢,与OT-li及VP-li神经元相接触,并在多数神经分泌副核的OT-li及Vp-li神经元周围,也有多寡不等的分布;而中等至高密度的5-HT-li纤维末梢,主要与各神经分泌副核内的OT-li或VP-li神经元相接触。说明5-HT-li和儿茶酚胺能传入纤维末梢,可能分别侧重调控不同神经分泌核区的大细胞神经分泌细胞群。     

大鼠下丘脑催产素及加压素样神经元与脑啡肽样传入纤维末梢的关系

用免疫组织化学ABC双标记法,显示大鼠下丘脑各大细胞神经分泌核团中催产素样免疫反应(OT-li)、加压素样免疫反应(VP-li)神经元、亮-脑啡肽样免疫反应(L-ENK-li)和甲-脑啡肽样免疫反应(M-ENK-li)纤维末梢,并对不同神经分泌核团内脑啡肽样传入纤维末梢与OT-li及VP-li神经元的关系加以分析。结果发现,L-ENK-li及M-ENK-li纤维末梢在下丘脑各神经分泌核团中,与OT-li及VP-li神经元均有一定程度的接触关系。L-ENK-li与M-ENK-li纤维末梢在第三脑室周、前连合核、背内侧和背外侧副核、穹窿前和后核的OT-li及VP-li神经元周围最密集,在视上核、室旁核次之,在血管周细胞群内的OT-li及VP-li神经元周围密度较低。这些神经分泌性核团内L-ENK-li纤维末梢,均较M-ENK-li纤维末梢密集。表明脑啡肽能传入纤维末梢,与视上核、室旁核及各神经分泌副核(除血管周细胞群外)中的OT-li及VP-li神经元,均有不同程度的接触关系。因此,脑啡肽能传入纤维末梢可能在大细胞神经分泌系统OT-li及VP-li神经元分泌活动的调节中,起较广泛的重要作用。     

大鼠下丘脑弓状核神经元的衰老性变化

选用青、中年和老年雄性大鼠各１０只，用形态计量学和体视学方法定量分析弓状核神经元年龄性变化。结果发现在老年大鼠弓状核，部分暗型和亮型神经元内粗面内质网排列紊乱、缩短和双层膜间隔增宽，线粒体嵴断裂、肿胀和空泡化，溶酶体，微管和颗粒小泡数减少；与青、中年组比较神经元数分别丢失３７％和２７％，核仁平均体积缩小３０％左右；     

大鼠下丘脑弓状核年龄性变化的电镜观察

电镜观察大鼠下丘脑弓状核超微结构的年龄变化。结果发现:衰老大鼠弓状核的年龄变化主要发生在弓状核中的暗细胞神经元,出现粗面内质网退化变短,排列失序;高尔基氏器缩小;多聚核蛋白体和神经内分泌物质明显减少。特别引人注目的是在部分暗细胞中出现由双层膜缠绕形成的膜性涡旋体结构。此外,在神经毯出现突触结构异常。突触厚度变薄、间断不连续;神经胶质细胞突起增多,并可进一步形成包绕树突、轴突终末、甚至突触的多层膜环绕的髓鞘样结构。上述研究结果提示,下丘脑弓状核超微结构的年龄性变化是导致神经内分泌系统衰老的主要原因之一。     

大鼠下丘脑加压素神经元的免疫细胞化学初步观察

用免疫细胞化学方法,观察到青年和老年大鼠下丘脑室旁核(PVN)视上核(SON)部位加压素免疫反应阳性神经元(VP神经元)较密集出现,并有粗细两类纤维。在PVN,有时可见一些VP神经元胞体或纤维接近或存在于室管膜层,甚至伸入第三脑室内。多数老年鼠PVN的VP神经元胞体染色浅,深染颗粒减少。发自PVN的粗细纤维都显著减少,染色也变浅。但VP细胞数量、形态、大小和青年鼠差不多。在老年鼠SON,VP神经元未见明显改变。     

The effect of increased longevity, produced by dietary restriction, on the neuronal population of area 17 in rat cerebral cortex

Area 17 of the brains of Sprague-Dawley derived rats, maintained on a limited ration of food to maintain their weights at the levels attained by two months of age, was compared with area 17 in control groups of rats fed ad lib. The oldest rats in the diet restricted group were sacrificed at 46 and 48 months of age, by which time their life spans had been extended about 12 months beyond the oldest age that rats fed ad lib achieve, for only few of the latter live as long as 33 months. In this study, the rats which were compared consisted of two groups of ad lib fed rats, one 3 and 6 months of age, and the other 33 months old, and two groups of diet restricted rats, one 26 months old and the other 46 to 48 month old rats (designated as 47 month old rats). Two indices were used to assess whether age affects the volume of area 17. One, the number of clusters of apical dendrites of layer V pyramidal cells per unit area of tangential sections, was the same in all groups, indicating that the lateral spread of area 17 did not alter with age. However, the other index, the thickness of area 17, did change with age, for area 17 was significantly thinner in the 47 month old diet restricted rats than in the other three groups. It was also found that the number of neuronal profiles in strips of sections passing through the entire depth of area 17 is decreased in the 47 month old rats, indicating that neurons had been lost from their cortices. This decrease in the number of neuronal profiles in the 47 month old rats was not due to nuclear shrinkage since the sizes of neuronal nuclei were not significantly different in the older ad lib and diet restricted rats. Determinations of neuronal packing densities in layers II/III, IV, V and VIa suggest that neurons are most frequently lost from the deeper cortical layers of the 47 month old rats, and in these layers large vacuolated spaces, the sizes of neuronal cell bodies, have been encountered. It is suggested that these spaces represent places from which neurons have been lost. It is concluded, therefore, that neurons are lost from area 17 in rats whose longevity is increased by diet restriction.     

大鼠下丘脑室旁核神经元的超微结构特征

在透射电镜下,我们观察到PVN大细胞具有四种不同的形态,认为属于同一类细胞分泌活性的不同时相:(1)合成相,粗面内质网非常丰富,(2)加工相:Golgi复合体发达,周围分布着一些神经分泌颗粒;(3)储存相:神经分泌颗粒明显增多:(4)转运相:细胞质内神经分泌颗粒很少,而在细胞周围可见一些充满神经分泌颗粒的突起。免疫电镜的结果也证实了VP阳性神经细胞具有类似的四种不同形态,其中在合成相,粗面内质网囊膜呈免疫阳性反应,还有一些PAP免疫复合物沉积在细胞质中。而在加工,储存和转运相,神经分泌颗粒呈免疫阳性反应。同样,小细胞亦具有三种不同形态特证,可能代表着不同的功能状态。