Abstract: Objective　To observe trends in brain structural changes with increasing age in Mongolian gerbils using medical imaging techniques.Methods　A Bruker Pharma Scan 7.0T MRI scanner was employed to acquire whole-brain T2-weighted structural images and diffusion tensor imaging (DTI) data of the corpus callosum, hippocampus, amygdala, striatum, sensory cortex, and motor cortex in Mongolian gerbils aged 3, 12, 18, and 26 months (6-7 animals per group, both sexes included). Fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from the DTI data.Results 1)FA values: compared with corpus callosum (0.47±0.08), left hippocampus (0.14±0.02), right hippocampus (0.13±0.03) in the 3 months group, the 18 months group showed significantly increase in the corpus callosum (0.62±0.07), left hippocampus (0.19±0.04), right hippocampus (0.18±0.02) (P<0.05). The 12 months group exhibited significantly increase in the right amygdala (0.21±0.03) (P<0.05). 2)MD values: compared with corpus callosum (8.15×10-4±5.43×10-5)/(mm2 /s), left hippocampus (7.53×10-4±2.32×10-5)/(mm2 /s), right hippocampus (7.35×10-4±4.55×10-5)/ (mm2 /s) in the 3 months group, the 18 months group demonstrated significantly decrease in the corpus callosum (6.41×10-4±6.51×10-5)/(mm2 /s), left hippocampus (6.52×10-4±2.08×10-5)/(mm2 /s), right hippocampus (6.54×10-4±3.25×10-5)/(mm2 /s)(P<0.05).Conclusion　The findings indicate that age-related structural changes in different brain regions of the Mongolian gerbil are asynchronous. However, an overall trend of initial increase followed by decline was observed. The period of structural maturation in the brain appears to occur between 12 and 18 months of age.

Key words: Gerbillinae, diffusion tensor imaging, brain, aging

摘要： 目的　应用医学影像学技术观察长爪沙鼠大脑结构随年龄增加的变化趋势。方法　使用Bruker Pharma Scan 7.0T MRI扫描仪,分别检测 3、12、18和26月龄组(每组6~7只,雌雄不限)长爪沙鼠的全脑T2结构像,以及胼胝 体、海马、杏仁核、纹状体、感觉皮层和运动皮层的DTI数据,通过计算最终得到FA值和MD值。结果　1)FA值方 面:与3月龄组长爪沙鼠的胼胝体(0.47±0.08)、左侧海马(0.14±0.02)、右侧海马(0.13±0.03)比较,18月龄组的 胼胝体(0.62±0.07)、左侧海马(0.19±0.04)、右侧海马(0.18±0.02)的FA值显著升高(P<0.05),12月龄组的右 侧杏仁核(0.21±0.03)的FA值显著升高(P<0.05);2)MD值方面:与3月龄组长爪沙鼠的胼胝体(8.15×10-4± 5.43×10-5)/(mm2 /s)、左侧海马(7.53×10-4±2.32×10-5)/(mm2 /s)、右侧海马(7.35×10-4±4.55×10-5)/(mm2 /s) 比较,18月龄组的胼胝体(6.41×10-4±6.51×10-5)/(mm2 /s)、左侧海马(6.52×10-4±2.08×10-5)/(mm2 /s)、右侧海 马(6.54×10-4±3.25×10-5)/(mm2 /s)的MD值显著降低(P<0.05)。结论　影像学检测结果提示,长爪沙鼠不同脑 区结构随年龄的变化并非同步,但总体呈现先升高后降低的趋势,大脑结构发育成熟期在12~18月龄。

关键词: 长爪沙鼠, 弥散张量成像, 大脑, 衰老