Yates M A, Markham J A, Anderson S E, Morris J R, Juraska J M
Psychology Department, University of Illinois Urbana-Champaign, Champaign, IL 61820, USA.
Brain Res. 2008 Jul 7;1218:1-12. doi: 10.1016/j.brainres.2008.04.055. Epub 2008 Apr 30.
During aging, changes in the structure of the cerebral cortex of the rat have been seen, but potential changes in neuron number remain largely unexplored. In the present study, stereological methods were used to examine neuron number in the medial prefrontal cortex and primary visual cortex of young adult (85-90 days of age) and aged (19-22 months old) male and female rats in order to investigate any age-related losses. Possible sex differences in aging were also examined since sexually dimorphic patterns of aging have been seen in other measures. An age-related loss of neurons (18-20%), which was mirrored in volume losses, was found to occur in the primary visual cortex in both sexes in all layers except IV. Males, but not females, also lost neurons (15%) from layer V/VI of the ventral medial prefrontal cortex and showed an overall decrease in volume of this region. In contrast, dorsal medial prefrontal cortex showed no age-related changes. The effects of aging clearly differ among regions of the rat brain and to some degree, between the sexes.
在衰老过程中，已观察到大鼠大脑皮质结构的变化，但神经元数量的潜在变化在很大程度上仍未得到探索。在本研究中，为了调查任何与年龄相关的神经元损失，采用了体视学方法来检查年轻成年（85 - 90日龄）和老年（19 - 22月龄）雄性和雌性大鼠内侧前额叶皮质和初级视觉皮质中的神经元数量。由于在其他测量中已观察到衰老的性别差异模式，因此还研究了衰老过程中可能存在的性别差异。在除IV层外的所有层中，两性的初级视觉皮质均出现与年龄相关的神经元损失（18 - 20%），且伴有体积损失。雄性大鼠腹内侧前额叶皮质的V/VI层神经元也有损失（15%），且该区域总体积减小，而雌性大鼠则未出现这种情况。相比之下，背内侧前额叶皮质未显示出与年龄相关的变化。衰老的影响在大鼠大脑的不同区域明显不同，并且在一定程度上存在性别差异。
