大鼠大脑皮质及皮质内有髓神经纤维的体视学研究

发布时间：2018-06-15 20:53

本文选题：皮质 + 有髓神经纤维　；参考：《重庆医科大学》2008年硕士论文

【摘要】： 关于老年大脑的结构改变,几十年来一直认为老年大脑皮质存在神经元的大量死亡,但是丹麦科学家运用新的体视学方法进行的定量研究发现正常老年大脑不存在显著性大脑皮质神经元死亡,而其白质体积存在显著性改变。我们发现了老年大脑白质的有髓神经纤维总长度显著性下降,但是,到目前为止,还没有运用新的体视学方法对大脑皮质神经纤维性别差异以及老年改变进行定量研究的报导。为了探讨中枢神经系统是否普遍存在老年性有髓神经纤维改变,我们将运用新的体视学方法和透射电子显微镜研究皮质内有髓神经纤维的总长度、总体积以及直径的性别差异和老年性改变。第一部分 1材料与方法 1.1 Long-Evans大鼠,6月龄10只,雌雄各5只;18月龄9只,雌性5只雄性4只;27月龄10只,雌雄各5只。 1.2从每只大鼠随机抽取一侧大脑半球,再从中随机抽取6块皮质组织块做成超薄切片,从每张超薄切片上随机抽取5个视野在透射电镜下放大4850倍拍照。 1.3运用体视学方法分别计算出不同年龄段雌雄性大鼠大脑皮质体积、皮质内有髓神经纤维总长度、总体积和皮质内有髓神经纤维平均直径。 2结果 2.1在年轻组,雄性大鼠大脑皮质体积、皮质内有髓神经纤维总长度和总体积均大于雌性大鼠,而雌性大鼠皮质内有髓神经纤维平均直径大于雄性大鼠,但雌雄大鼠之间的差异不具有显著性(p0.05)。 2.2在中老年组,虽然雄性大鼠大脑皮质体积、皮质内有髓神经纤维总长度、总体积和皮质内有髓神经纤维的平均直径均大于雌性大鼠,但这些差异均不具有显著性(p0.05)。 2.3在老年组,雄性大鼠大脑皮质体积、皮质内有髓神经纤维总长度、总体积以及有髓神经纤维平均直径小于雌性,但这些差异均不具有显著性(p0.05)。第二部分 1材料与方法 1.1 6月龄Long-Evans大鼠10只,雌雄各5只;18月龄Long-Evans大鼠9只,雌性5只,雄性4只;27月龄Long-Evans大鼠10只,雌雄各5只 1.2从每只大鼠随机抽取一侧大脑半球,再从中随机抽取6块皮质组织块做成超薄切片,从每张切片上随机抽取5个视野在透射电镜下放大4850倍拍照。 1.3运用体视学方法分别计算出年轻组、中老年组和老年组大鼠大脑皮质体积、皮质内有髓神经纤维总长度、总体积和皮质内有髓神经纤维平均直径。 2结果 2.1中老年大鼠大脑皮质体积、皮质内有髓神经纤维总长度、总体积和皮质内有髓神经纤维平均直径与年轻组大鼠不存在显著性差异(p0.05)。 2.2老年组大鼠大脑皮质体积、皮质内有髓神经纤维总长度分别较年轻大鼠显著性下降了18.5%和35.4%(p0.01),但老年组大鼠皮质内有髓神经纤维总体积与年轻大鼠之间不存在显著性差异,老年组大鼠皮质内有髓神经纤维平均直径较年轻大鼠显著性增加23.3%(p0.05)。 2.3老年组大鼠大脑皮质体积、皮质内有髓神经纤维总长度分别较中老年组大鼠显著性下降15.5%和33.9%(p0.01),但老年组大鼠皮质内有髓神经纤维总体积与中老年组大鼠之间不存在显著性差异,老年组大鼠皮质内有髓神经纤维平均直径较中老年组显著性增加20.0%(p0.05)。全文结论 1.本研究在国际上首次把新的体视学方法和电子显微镜技术结合起来定量研究大鼠大脑皮质及皮质内有髓神经纤维的性别差异和老年改变。 2.获得了年轻组、中老年组和老年组雄性和雌性大鼠大脑皮质体积、皮质内有髓神经纤维的总长度和总体积及纤维平均直径的基本数值,这些数值为今后的研究提供了重要的参考数据。 3.发现不同年龄段雌雄性Long-Evans大鼠大脑皮质总体积、皮质内有髓神经纤维总长度、总体积和有髓神经纤维平均直径之间均不存在显著性性别差异。 4.发现存在老年性大脑皮质萎缩和皮质内有髓神经纤维总长度显著性下降,老年大鼠皮质内有髓神经纤维总长度的下降主要是由于细小直径的有髓神经纤维改变所致。 5.发现大鼠大脑皮质有髓神经纤维老年改变的出现要晚于白质内有髓神经纤维的老年改变。
[Abstract]:With regard to structural changes in the brain of the elderly, there have been decades of thought that there is a large number of neuronal deaths in the aged brain cortex, but a quantitative study by Danish scientists using new stereological methods found no significant cerebral cortical neuron death in the normal brain, and a significant change in the volume of white matter. The total length of the myelinated nerve fibers in the white matter of the aged brain has decreased significantly, but up to now, there has not been a new stereological approach to the quantitative study of the gender differences in the cerebral cortex and the changes in the elderly. A new stereological method and a transmission electron microscope will be used to study the total length, total volume, and diameter of the myelinated nerve fibers in the cortex and the age-related changes in the aged.
Part one
1 materials and methods
1.1 Long-Evans rats, 6 month old 10, 5 males and 5 females, 18 month old 9, 5 female 4, 27 month old 10, male and female 5.
1.2 from each rat randomly selected one hemisphere of the brain, and then randomly selected 6 cortical tissue blocks to make ultra thin slices. From each ultra thin slice, 5 fields were randomly selected for 4850 times magnified under transmission electron microscope.
1.3 the volume of cerebral cortex in male and female rats of different ages was calculated by stereological method. The total length, total volume and average diameter of myelinated nerve fibers in the cortex were measured in the cortex.
2 Results
2.1 in the young group, the volume of the cerebral cortex, the total length and the total volume of the myelinated nerve fibers in the cortex of the male rats were greater than that of the female rats, but the average diameter of the myelinated nerve fibers in the cortex of the female rats was greater than that of the male rats, but the difference between the male and female rats was not significant (P0.05).
2.2 in the middle and old age group, the average diameter of the medullary nerve fibers in the cortex of the male rats, the total volume of the total volume and the mean diameter of the myelinated nerve fibers in the cortex were all larger than that of the female rats, but these differences were not significant (P0.05).
2.3 in the elderly group, the volume of cerebral cortex in the male rats, the total length of the myelinated nerve fibers in the cortex, the total volume and the average diameter of the myelinated nerve fibers were less than that of the female, but these differences were not significant (P0.05).
The second part
1 materials and methods
There were 10 Long-Evans rats in 1.16 months old, 5 males and 5 females, 9 rats in 18 month old Long-Evans rats, 5 females, 4 males, 27 month old 10 rats, 5 males and females.
1.2 from each rat, each rat was randomly selected from one side of the cerebral hemisphere, and then 6 pieces of cortical tissue were randomly selected to make a super thin slice. 5 fields were randomly selected from each slice and amplified 4850 times under transmission electron microscope.
1.3 the volume of cerebral cortex, the total length of myelinated nerve fibers, the total volume of the medullary nerve fibers in the cortex and the average diameter of the myelinated nerve fibers in the cortex were calculated by the stereological method.
2 Results
2.1 the volume of cerebral cortex, the total length of the myelinated nerve fibers in the cortex, the total volume and the average diameter of the myelinated nerve fibers in the cortex were not significantly different from those of the young rats (P0.05).
2.2 the volume of cerebral cortex and the total length of myelinated nerve fibers in the cortex of the aged group decreased by 18.5% and 35.4% (P0.01), respectively, but there was no significant difference between the total medullary nerve fiber volume and the young rats in the aged group. The average diameter of the myelinated nerve fibers in the cortex of the old group was larger than that of the younger rats. The rats were significantly increased by 23.3% (P0.05).
2.3 the volume of cerebral cortex and the total length of myelinated nerve fibers in the cortex of the aged rats were significantly decreased by 15.5% and 33.9% (P0.01), respectively, but there was no significant difference between the total medullary nerve fibers in the cortex of the aged group and the elderly rats. The average diameter of the myelinated nerve fibers in the old age group was more than that of the old rats. The significant increase in the middle and old age group was 20% (P0.05).
Full text conclusion
1. this study combines the new stereology and electron microscopy for the first time to quantify the gender differences and age-related changes in the myelinated nerve fibers in the cortex and cortex of the rat.
2. the volume of the cerebral cortex, the total length and total volume of the myelinated nerve fibers and the average diameter of the fibers were obtained in the young, the middle and old age group and the aged group, and the total volume and the average diameter of the fibers. These values provide important reference data for future research.
3. the total volume of the cerebral cortex was found in the male and female Long-Evans rats of different ages. There was no significant gender difference between the total medullary nerve fiber length, the total volume and the average diameter of the myelinated nerve fibers in the cortex.
4. it was found that the atrophy of cerebral cortex in the aged and the total length of the myelinated nerve fibers in the cortex decreased significantly. The decrease of the total length of the myelinated nerve fibers in the cortex of the aged rats was mainly due to the change of the medullary nerve fibers in the small diameter.
5. it was found that the age-related changes of myelinated nerve fibers in the cerebral cortex were later than those in the white matter.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R322

【共引文献】