Research Laboratory for Stereology and Neuroscience, Bispebjerg University Hospital, Copenhagen, NV, Denmark.
Neurobiol Aging. 2012 May;33(5):1009.e1-9. doi: 10.1016/j.neurobiolaging.2011.10.017. Epub 2011 Nov 26.
The present study is aimed to assess age-related structural changes in corpus callosum with stereology in 21 postmortem human brains without neuropathology, of age 65-75 (Group A, n = 7), 80-85 (Group B, n = 7), and 94-105 (Group C, n = 7) years. Cross-sectional area, fiber number and density decrease in Group B compared with Group A, then remain unchanged in Group C. Mean fiber diameter increases with age. Cross-sectional area shows strong positive correlation to fiber numbers and negative correlation to mean fiber thickness. With age, modest but significant change in fiber size including a decrease in the percentage of 1-2-μm fibers and an increase in 2-3-μm fibers was observed. Fiber density shows a steeper decline with age in the anterior compared with posterior segments. Neurodegeneration is an ongoing process where the anterior corpus callosum is more susceptible to age-related degeneration. Corpus callosum cross-sectional area atrophy is mostly related to decline in fiber number and density rather than demyelination, with preferential disruption of small caliber fibers.
本研究旨在通过体视学评估 21 例无神经病理学改变的人类死后大脑胼胝体的年龄相关结构变化，年龄分别为 65-75 岁（A 组，n=7）、80-85 岁（B 组，n=7）和 94-105 岁（C 组，n=7）。B 组与 A 组相比，横截面积、纤维数量和密度减少，而 C 组则保持不变。平均纤维直径随年龄增长而增加。横截面积与纤维数量呈正相关，与平均纤维厚度呈负相关。随着年龄的增长，纤维大小发生了适度但显著的变化，包括 1-2μm 纤维的百分比减少和 2-3μm 纤维的增加。与后段相比，前部的纤维密度随年龄的增长下降更为陡峭。神经退行性变是一个持续的过程，在前部胼胝体更容易受到与年龄相关的退化影响。胼胝体横截面积萎缩主要与纤维数量和密度的下降有关，而不是脱髓鞘，小口径纤维优先受到破坏。
