Landfield P W, Wurtz C, Lindsey J D
Brain Res Bull. 1979 Nov-Dec;4(6):757-63. doi: 10.1016/0361-9230(79)90009-1.
Synaptic vesicle populations were quantified in Schaffer-commissural synapses which terminate on CA1 pyramidal cell apical dendrites, in aging and young-mature rats. Vesicles were found to be reduced with age, and this effect was most pronounced in the oldest animals (e.g., 28 months) within the aged group. Numerical density of synaptic vesicles in aged rat hippocampus was reduced whether expressed as vesicles per terminal, vesicles per mu 2 of terminal, or vesicles per mu2 of terminal corrected for shrinkage or swelling as assessed by mitochondrial cross-sectional diameters. Counted synaptic terminal areas were not significantly different in the aged animals, although a trend toward reduced terminal size with aging was seen. The latter observation apparently rules out increased terminal swelling in aged rat synapses as a basis for reduced vesicle density. In some rats, neurophysiological studies were concomitantly performed. A significant correlation was found between the amplitude of the monosynaptic population spike after 20 min of 4 Hz stimulation of the Schaffer-commissural fibers and synaptic vesicle populations in terminals of these stimulated pathways. However, because of a low n this result must be viewed as preliminary.
在老年和年轻成熟大鼠中，对终止于CA1锥体细胞顶树突的海马联合突触中的突触小泡群体进行了定量分析。发现小泡数量随年龄增长而减少，且这种效应在老年组中最老的动物（如28个月大）中最为明显。无论以每个终末的小泡数、每平方微米终末的小泡数，还是根据线粒体横截面积评估校正了收缩或肿胀后的每平方微米终末的小泡数来表示，老年大鼠海马中突触小泡的数值密度均降低。尽管观察到随着年龄增长终末大小有减小的趋势，但老年动物中计数的突触终末面积并无显著差异。后一观察结果显然排除了老年大鼠突触中终末肿胀增加是小泡密度降低的基础这一可能性。在一些大鼠中，同时进行了神经生理学研究。在对海马联合纤维进行4Hz刺激20分钟后，单突触群体峰电位的幅度与这些受刺激通路终末中的突触小泡群体之间存在显著相关性。然而，由于样本量较小，该结果必须视为初步结果。
