Laboratory of Neuroscience, Department of Physical Therapy, College of Rehabilitation Science, Daegu University, Gyeongsan, 712-714, South Korea.
Cell Mol Neurobiol. 2013 Jan;33(1):75-84. doi: 10.1007/s10571-012-9873-8. Epub 2012 Sep 13.
Alpha-synuclein (α-syn), as a neuroprotein, is expressed in neural tissue, and it is related to a synaptic transmission and neuronal plasticity. In this study, we compared the distribution and immunoreactivity of α-syn and related gliosis in hippocampus between young adult (2-3 years) and aged (10-12 years) beagle dogs. In both groups, α-syn immunoreactivity was detected in neuropil of all the hippocampal sub-regions, but not in neuronal somata. In the aged hippocampus, α-syn immunoreactivity was apparently increased in mossy fibers compared to that in the adult dog. In addition, α-syn protein level was markedly increased in the aged hippocampus. On the other hand, GFAP and Iba-1 immunoreactivity in astrocytes and microglia, respectively, were increased in all the hippocampal sub-regions of the aged group compared to that in the adult group: especially, their immunoreactivity was apparently increased around mossy fibers. In addition, in this study, we could not find any expression of α-syn in astrocytes and microglia. These results indicate that α-syn immunoreactivity apparently increases in the aged hippocampus and that GFAP and Iba-1 immunoreactivity are also apparently increased at the regions with increased α-syn immunoreactivity. This increase in α-syn expression might be a feature of normal aging.
α-突触核蛋白（α-syn）作为一种神经蛋白，在神经组织中表达，与突触传递和神经元可塑性有关。在这项研究中，我们比较了年轻成年（2-3 岁）和老年（10-12 岁）比格犬海马体中α-syn 的分布和免疫反应性以及相关的神经胶质增生。在两组中，α-syn 免疫反应性均在海马体所有亚区的神经突中检测到，但不在神经元胞体中检测到。在老年海马体中，与成年犬相比，苔藓纤维中的α-syn 免疫反应性明显增加。此外，α-syn 蛋白水平在老年海马体中明显增加。另一方面，星形胶质细胞和小胶质细胞中的 GFAP 和 Iba-1 免疫反应性在老年组的所有海马体亚区均高于成年组：特别是，它们的免疫反应性在苔藓纤维周围明显增加。此外，在这项研究中，我们未在星形胶质细胞和小胶质细胞中发现任何α-syn 的表达。这些结果表明，α-syn 免疫反应性在老年海马体中明显增加，GFAP 和 Iba-1 免疫反应性在α-syn 免疫反应性增加的区域也明显增加。这种α-syn 表达的增加可能是正常衰老的特征。
