Department of Rehabilitation Medicine, First people's Hospital of Chenzhou, Chenzhou 423000, Hunan province, China.
Neurol Sci. 2013 Jun;34(6):963-9. doi: 10.1007/s10072-012-1173-z. Epub 2012 Aug 8.
The objective of this study is to examine whether neuron loss occurs in SAMP8 and whether neuron loss is correlated with cognitive deficits of these mice. Neuronal loss is considered as one of the most important pathological hallmarks of Alzheimer disease (AD). In addition to the early-onset, irreversible, severe deficits of learning and memory, SAMP8 mice show spontaneous age-related neurodegenerative changes and other characteristics seen in AD patients, such as amyloid plaques and neurofibrillary tangles. However, it is still unknown whether neuron loss occurs in SAMP8 and whether neuron loss is correlated with cognitive deficits of these mice. We employed 8-month-old SAMP8 and SAMR1 mice to investigate the cognitive function and neuron numbers. The behaviors were examined by the grading score of senescence and Morris water maze (MWM) test, the neuron number in hippocampus was estimated by the optical fractionator technique. The grading score of senescence and MWM test demonstrated that SAMP8 exhibited notable age-related changes in appearance and cognitive function. Moreover, severe hippocampal neuron loss was found in SAMP8 as determined by the optical fractionator stereological method. Compared to SAMR1, the neuron number of CA1, CA3 and DG in SAMP8 was reduced by 15.6, 19.8 and 20.2 %, respectively, and the neuron loss in hippocampus was associated with cognitive deficits. Collectively, these results suggest that hippocampal neuronal loss is well correlated with learning and memory deficits in SAMP8 and SAMP8 represents an important mouse model for AD.
本研究旨在探讨 SAMP8 是否存在神经元丢失，以及神经元丢失是否与这些小鼠的认知缺陷相关。神经元丢失被认为是阿尔茨海默病（AD）最重要的病理标志之一。除了学习和记忆的早期、不可逆转、严重缺陷外，SAMP8 小鼠还表现出自发性年龄相关的神经退行性变化和 AD 患者的其他特征，如淀粉样斑块和神经纤维缠结。然而，目前尚不清楚 SAMP8 是否存在神经元丢失，以及神经元丢失是否与这些小鼠的认知缺陷相关。我们使用 8 月龄的 SAMP8 和 SAMR1 小鼠来研究认知功能和神经元数量。通过衰老分级评分和 Morris 水迷宫（MWM）测试来评估行为，使用光学分束技术估计海马神经元数量。衰老分级评分和 MWM 测试表明，SAMP8 表现出明显的与年龄相关的外观和认知功能变化。此外，通过光学分束体视学法发现 SAMP8 存在严重的海马神经元丢失。与 SAMR1 相比，SAMP8 的 CA1、CA3 和 DG 区神经元数量分别减少了 15.6%、19.8%和 20.2%，海马神经元丢失与认知缺陷相关。综上所述，这些结果表明，海马神经元丢失与 SAMP8 的学习和记忆缺陷密切相关，SAMP8 是 AD 的重要小鼠模型。
