中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2017, Vol. 12 ›› Issue (9): 1485-1491.doi: 10.4103/1673-5374.213559

• 原著:退行性病与再生 • 上一篇    下一篇

DTI技术中FA值和MD值观察鱼藤酮帕金森病模型多巴胺能神经元早期退行性改变

  

  • 收稿日期:2017-06-06 出版日期:2017-09-15 发布日期:2017-09-15
  • 基金资助:

    河北省科技项目（1427777118D）

Detecting dopaminergic neuronal degeneration using diffusion tensor imaging in a rotenone-induced rat model of Parkinson’s disease: fractional anisotropyand mean diffusivity values

 Lan-xiang Liu1, Dan Du1, Tao Zheng1, Yuan Fang1, Yan-sheng Chen1, Hui-ling Yi1, Qing-yuan He2, Da-wei Gao3, Qing-lei Shi4   

  1. 1 Department of Magnetic Resonance Imaging, First Hospital of Qinhuangdao, Qinhuangdao, Hebei Province, China
    2 Department of Radiology, Peking University Third Hospital, Beijing, China
    3 College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei Province, China
    4 Scientific Clinical Specialist, Siemens Ltd., Beijing, China
  • Received:2017-06-06 Online:2017-09-15 Published:2017-09-15
  • Contact: Lan-xiang Liu,liulanxiang66@sina.com.
  • Supported by:

    This work was financially supported by the Research Grant of Hebei Province Science and Technology Project of China, No.1427777118D.

PDF

436

摘要：

研究证实，多巴胺含量在基底节中减少的程度与黑质致密部多巴胺能神经元丢失的严重程度密切相关，当黑质致密部多巴胺神经元丢失达50％以上、基底节区多巴胺含量减少到80%以上时可出现帕金森的临床症状，故使帕金森病临床诊断标准缺乏早期诊断的时效性。近年来，扩散张量成像(DTI)检测平均扩散系数(MD)及部分各向异性(FA)展示出有效反映脑微结构改变的特点。当微观屏障破坏和细胞外液体积聚时MD值增加，当微结构(如髓鞘)的完整性受到破坏时FA值减低，但这些变化是否能够反映帕金森病的早期病理变化目前尚无共识。实验设计将大鼠右侧黑质颅内注射鱼藤酮建立帕金森病大鼠模型为实验组，大鼠右侧黑质颅内注射生理盐水为对照组。以DTI检测发现，对应帕金森病发病早期，建模后1，2，4，6周，与对照组相比，实验组右侧黑质FA值降低，MD值增加。实验组右侧黑质建模后第4周FA值较第6周降低。实验组右侧纹状体MD值建模后第1周较第6周明显升高。结果说明采用DTI技术检测帕金森大鼠模型建模后4周脑部的MD及FA值，能有效反映多巴胺能神经元早期退行性改变的情况，髓鞘完整性受到破坏出现的FA值变化可能较MD值更具早期诊断意义。

orcid:0000-0002-7434-4434(Lan-xiang Liu)

关键词: 神经再生, 弥散张量成像, 部分各向异性, 扩散系数, 磁共振成像, 帕金森病, 鱼藤酮, 神经退行性疾病, 生物标记, 黑质, 酪氨酸羟化酶

Abstract:

Dopamine content in the basal ganglia is strongly associated with the degree of dopaminergic neuron loss in the substantia nigra pars compacta.Symptoms of Parkinson’s disease might not arise until more than 50% of the substantia nigra pars compacta is lost and the dopamine content in the basal ganglia is reduced by more than 80%. Greater diagnostic sensitivity and specificity would allow earlier detection of Parkinson’s disease. Diffusion tensor imaging is a recently developed magnetic resonance imaging technique that measures mean diffusivity and fractional anisotropy, and responds to changes in brain microstructure. When the microscopic barrier (including cell membranes,microtubules and other structures that interfere with the free diffusion of water) is destroyed and extracellular fluid volume accumulates,the mean diffusivity value increases; when the integrity of the microstructure (such as myelin) is destroyed, fractional anisotropy value decreases. However, there is no consensus as to whether these changes can reflect the early pathological alterations in Parkinson’s disease.Here, we established a rat model of Parkinson’s disease by injecting rotenone (or sunflower oil in controls) into the right substantia nigra.Diffusion tensor imaging results revealed that in the stages of disease, at 1, 2, 4, and 6 weeks after rotenone injection, fractional anisotropy value decreased, but mean diffusivity values increased in the right substantia nigra in the experimental group. Fractional anisotropy values were lower at 4 weeks than at 6 weeks in the right substantia nigra of rats from the experimental group. Mean diffusivity values were markedly greater at 1 week than at 6 weeks in the right corpus striatum of rats from the experimental group. These findings suggest that mean diffusivity and fractional anisotropy values in the brain of rat models of Parkinson’s disease 4 weeks after model establishment can reflect early degeneration of dopaminergic neurons. The change in fractional anisotropy values after destruction of myelin integrity is likely to be of greater early diagnostic significance than the change in mean diffusivity values.
 

Key words: nerve regeneration, diffusion tensor imaging, fractional anisotropy, mean diffusivity, magnetic resonance imaging, Parkinson’s disease, rotenone, neurodegenerative disease, biomarkers, substantia nigra, tyrosine hydroxylase, neural regeneration