摘要
目的研究大鼠胼胝体中段和压部体积及其内有髓神经纤维的老年改变。方法运用新的体视学方法和透射电镜技术定量研究成年、中年和老年雌性Long-Evans大鼠胼胝体中段和压部的体积、有髓神经纤维的长度密度、总长度、有髓神经纤维的直径。结果胼胝体中段体积在老年组比成年组和中年组分别显著降低21.5%和18.1%,而胼胝体压部体积变化不明显。胼胝体中段和压部有髓神经纤维的长度密度、总长度、平均直径均没有明显的老年改变。老年组大鼠大脑胼胝体中段内直径为0.7～0.8μm的有髓神经纤维总长度比成年组大鼠显著减少3.45km,直径为1.5～1.6μm的有髓神经纤维的总长度比成年组显著增加0.5km。老年组大鼠大脑胼胝体压部内直径为1.2～1.3μm和1.4～1.5μm的有髓神经纤维总长度分别较成年组大鼠显著增加0.123km和0.108km。结论老年大脑胼胝体压部没有发生显著性萎缩。老年大脑胼胝体中段体积显著性下降,胼胝体中段内小直径的有髓神经纤维总长度显著性降低可能是老年胼胝体中段体积显著性下降的重要原因之一。
Objective To investigate the age-related changes in the volumes of the mid-region and splenium of corpus callosum and the myelinated fibers in these areas of corpus callosum.MethodsThe volume of the mid-region and splenium of corpus callosum,and the length density,total length and diameters of myelinated fibers in these area of adult,middle-aged and old-aged female Long-Evans rats were studied by the use of electron microscope technique and unbiased stereological techniques.ResultsWhen compared to adult rats and middle-aged rats,the volume of the mid-region in corpus callosum of old-aged rats was significantly decreased by 21.5% and 18.1% respectively.However,there was no significant change in the volume of the splenium in corpus callosum among adult,middle-aged and old-aged rats.There was no significant change in the length density,total length and mean diameter of the myelinated fibers in the mid-region and splenium in corpus callosum among adult,middle-aged and old-aged rats.In the mid-region of corpus callosum of old-aged rats,the total length of the myelinated fibers at a diameter of 0.7 to 0.8 μm was significantly decreased by 3.45 km,and the total length of the myelinated fibers at a diameter of 1.5 to 1.6 μm was significantly increased by 0.5 km,respectively,when compared to adult rats.In the splenium of corpus callosum of old-aged rat,the total lengths of the myelinated fibers at a diameter of 1.2 to 1.3 μm and 1.4 to 1.5 μm were significantly increased by 0.123 km and 0.108 km,respectively,when compared to young rats.ConclusionThe splenium region of rat corpus callosum doesn＇t significantly shrinks with age.The mid-region of rat corpus callosum significantly shrunks with age,which might mainly be due to the significant decline of total length of myelinated fibers with smaller diameters in this region.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2010年第20期2185-2188,共4页
Journal of Third Military Medical University
基金
国家自然科学基金(30973155)
教育部博士培养基金(200806310007)
重庆医科大学重点项目(XB2D200801)
重庆市自然科学基金(CSTC2009BA5035)~~
关键词
胼胝体
有髓神经纤维
老年改变
体视学
corpus callosum
myelinated nerve fibers
age-related changes
stereology
