Age-Induced Loss of Mossy Fibre Synapses on CA3 Thorns in the CA3 Stratum Lucidum.
Age-Induced Loss of Mossy Fibre Synapses on CA3 Thorns in the CA3 Stratum Lucidum.
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DOI：
10.1155/2013/839535
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Stewart MG
中科院分区：
文献类型：
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作者：
Ojo B;Davies H;Rezaie P;Gabbott P;Colyer F;Kraev I;Stewart MG
高级衰老与海马体退化和轻度认知能力下降有关。海马区CA3透明层(CA3-SL)接受齿状回巨型苔藓纤维束的神经元输入，但对这种突触联系与衰老的完整性知之甚少。用连续电子显微镜和无偏体视学方法，研究了青年(4个月龄)、中年(12个月龄)和老年(28个月龄)Wistar大鼠CA3-SL内CA3棘突上苔藓纤维突触的年龄相关性变化。我们的数据显示，虽然CA3的体积随着年龄的增长而增加，但12和28个月龄的动物与4个月龄的动物相比，CA3-SL内的突触密度显著降低(40-45%)。我们还提供了初步的数据显示，晚期衰老的CA3神经束明显充满了脂褐素和吞噬酶体阳性，激活了小胶质细胞的突起，并改变了血管周围的病理。这些数据表明，CA3-SL的突触密度在衰老过程中显著受损，并伴随着潜在的显著的超微结构胶质细胞和微血管变化。
Advanced ageing is associated with hippocampal deterioration and mild cognitive decline. The hippocampal subregion CA3 stratum lucidum (CA3-SL) receives neuronal inputs from the giant mossy fibre boutons of the dentate gyrus, but relatively little is known about the integrity of this synaptic connection with ageing. Using serial electron microscopy and unbiased stereology, we examined age-related changes in mossy fibre synapses on CA3 thorny excrescences within the CA3-SL of young adults (4-month-old), middle-aged (12-month-old), and old-aged (28-month-old) Wistar rats. Our data show that while there is an increase in CA3 volume with ageing, there is a significant (40–45%) reduction in synaptic density within the CA3-SL of 12- and 28-month-old animals compared with 4-month-old animals. We also present preliminary data showing that the CA3 neuropil in advanced ageing was conspicuously full of lipofuscin and phagolysosome positive, activated microglial cellular processes, and altered perivascular pathology. These data suggest that synaptic density in the CA3-SL is significantly impaired in ageing, accompanied by underlying prominent ultrastructural glial and microvascular changes.