本文選題：皮質(zhì) + 有髓神經(jīng)纖維��； 參考：《重慶醫(yī)科大學(xué)》2008年碩士論文

【摘要】： 關(guān)于老年大腦的結(jié)構(gòu)改變,幾十年來一直認(rèn)為老年大腦皮質(zhì)存在神經(jīng)元的大量死亡,但是丹麥科學(xué)家運(yùn)用新的體視學(xué)方法進(jìn)行的定量研究發(fā)現(xiàn)正常老年大腦不存在顯著性大腦皮質(zhì)神經(jīng)元死亡,而其白質(zhì)體積存在顯著性改變。我們發(fā)現(xiàn)了老年大腦白質(zhì)的有髓神經(jīng)纖維總長度顯著性下降,但是,到目前為止,還沒有運(yùn)用新的體視學(xué)方法對(duì)大腦皮質(zhì)神經(jīng)纖維性別差異以及老年改變進(jìn)行定量研究的報(bào)導(dǎo)。為了探討中樞神經(jīng)系統(tǒng)是否普遍存在老年性有髓神經(jīng)纖維改變,我們將運(yùn)用新的體視學(xué)方法和透射電子顯微鏡研究皮質(zhì)內(nèi)有髓神經(jīng)纖維的總長度、總體積以及直徑的性別差異和老年性改變。 第一部分 1材料與方法 1.1 Long-Evans大鼠,6月齡10只,雌雄各5只;18月齡9只,雌性5只雄性4只;27月齡10只,雌雄各5只。 1.2從每只大鼠隨機(jī)抽取一側(cè)大腦半球,再從中隨機(jī)抽取6塊皮質(zhì)組織塊做成超薄切片,從每張超薄切片上隨機(jī)抽取5個(gè)視野在透射電鏡下放大4850倍拍照。 1.3運(yùn)用體視學(xué)方法分別計(jì)算出不同年齡段雌雄性大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積和皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑。 2結(jié)果 2.1在年輕組,雄性大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度和總體積均大于雌性大鼠,而雌性大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑大于雄性大鼠,但雌雄大鼠之間的差異不具有顯著性(p0.05)。 2.2在中老年組,雖然雄性大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積和皮質(zhì)內(nèi)有髓神經(jīng)纖維的平均直徑均大于雌性大鼠,但這些差異均不具有顯著性(p0.05)。 2.3在老年組,雄性大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積以及有髓神經(jīng)纖維平均直徑小于雌性,但這些差異均不具有顯著性(p0.05)。 第二部分 1材料與方法 1.1 6月齡Long-Evans大鼠10只,雌雄各5只;18月齡Long-Evans大鼠9只,雌性5只,雄性4只;27月齡Long-Evans大鼠10只,雌雄各5只 1.2從每只大鼠隨機(jī)抽取一側(cè)大腦半球,再從中隨機(jī)抽取6塊皮質(zhì)組織塊做成超薄切片,從每張切片上隨機(jī)抽取5個(gè)視野在透射電鏡下放大4850倍拍照。 1.3運(yùn)用體視學(xué)方法分別計(jì)算出年輕組、中老年組和老年組大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積和皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑。 2結(jié)果 2.1中老年大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積和皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑與年輕組大鼠不存在顯著性差異(p0.05)。 2.2老年組大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度分別較年輕大鼠顯著性下降了18.5%和35.4%(p0.01),但老年組大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維總體積與年輕大鼠之間不存在顯著性差異,老年組大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑較年輕大鼠顯著性增加23.3%(p0.05)。 2.3老年組大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度分別較中老年組大鼠顯著性下降15.5%和33.9%(p0.01),但老年組大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維總體積與中老年組大鼠之間不存在顯著性差異,老年組大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維平均直徑較中老年組顯著性增加20.0%(p0.05)。 全文結(jié)論 1.本研究在國際上首次把新的體視學(xué)方法和電子顯微鏡技術(shù)結(jié)合起來定量研究大鼠大腦皮質(zhì)及皮質(zhì)內(nèi)有髓神經(jīng)纖維的性別差異和老年改變。 2.獲得了年輕組、中老年組和老年組雄性和雌性大鼠大腦皮質(zhì)體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維的總長度和總體積及纖維平均直徑的基本數(shù)值,這些數(shù)值為今后的研究提供了重要的參考數(shù)據(jù)。 3.發(fā)現(xiàn)不同年齡段雌雄性Long-Evans大鼠大腦皮質(zhì)總體積、皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度、總體積和有髓神經(jīng)纖維平均直徑之間均不存在顯著性性別差異。 4.發(fā)現(xiàn)存在老年性大腦皮質(zhì)萎縮和皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度顯著性下降,老年大鼠皮質(zhì)內(nèi)有髓神經(jīng)纖維總長度的下降主要是由于細(xì)小直徑的有髓神經(jīng)纖維改變所致。 5.發(fā)現(xiàn)大鼠大腦皮質(zhì)有髓神經(jīng)纖維老年改變的出現(xiàn)要晚于白質(zhì)內(nèi)有髓神經(jīng)纖維的老年改變。
[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.
【學(xué)位授予單位】：重慶醫(yī)科大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2008
【分類號(hào)】：R322

【共引文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 汪浩;年齡及性別相關(guān)的大鼠視皮層細(xì)胞的功能衰退[D];中國科學(xué)技術(shù)大學(xué);2006年

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本文編號(hào)：2023617