Departments of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612, United States.
Neurobiol Aging. 2012 Jan;33(1):35-42. doi: 10.1016/j.neurobiolaging.2010.02.006. Epub 2010 Mar 31.
Dopaminergic neurons in the substantia nigra produce dopamine for the nigrostriatal pathway that facilitates motor function. Postmortem examinations demonstrate an age-related loss of cells in the substantia nigra, with most of the cell loss focused on the dorsal substantia nigra compared with the ventral substantia nigra. The current study used diffusion tensor imaging (DTI) to provide the first in vivo assessment of age-related degeneration in specific segments of the substantia nigra of humans. Measures extracted from DTI of 16 young adults (19-27 years) and 15 older adults (55-71 years) showed that in the dorsal substantia nigra, fractional anisotropy was reduced and radial diffusivity was increased with age. In the ventral substantia nigra and red nucleus, there were no differences across age for the DTI measures. DTI provides a noninvasive technique that accurately reflects the established pattern of age-related cell loss in the dorsal and ventral substantia nigra, further suggesting the robust potential for using DTI to characterize degeneration in the nigrostriatal pathway in both health and disease.
黑质中的多巴胺能神经元产生多巴胺，用于黑质纹状体通路，促进运动功能。尸检研究表明，黑质细胞随年龄增长而逐渐丧失，与腹侧黑质相比，背侧黑质的细胞丧失更为集中。本研究采用弥散张量成像（DTI）对人类黑质特定节段的年龄相关性退变进行了首次活体评估。从 16 名年轻成年人（19-27 岁）和 15 名老年人（55-71 岁）的 DTI 中提取的测量值表明，在背侧黑质中，各向异性分数随年龄降低，径向弥散度随年龄增加。在腹侧黑质和红核中，DTI 测量值在不同年龄组之间没有差异。DTI 提供了一种非侵入性技术，可以准确反映背侧和腹侧黑质中与年龄相关的细胞丧失模式，这进一步表明，使用 DTI 来描述健康和疾病状态下黑质纹状体通路的退变具有强大的潜力。
