Zhong Yu-Feng, Tang Zuo-Hua, Qiang Jin-Wei, Wu Ling-Jie, Wang Rong, Wang Jie, Jin Li-Xin, Xiao Ze-Bin
Department of Radiology, Jinshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Department of Radiology, Eye and ENT Hospital of Shanghai Medical College, Fudan University, Shanghai, China.
Department of Radiology, Eye and ENT Hospital of Shanghai Medical College, Fudan University, Shanghai, China.
Neurosci Lett. 2017 Jan 1;636:248-253. doi: 10.1016/j.neulet.2016.11.030. Epub 2016 Nov 15.
For humans and non-human primates, the alteration of the visual pathway's white matter fibers after visual deprivation has been partially explored. However, the changes in the optic tracts after the transection of the optic nerve have not been well characterized. In the current study, we attempted to investigate the differences in optic tracts between normal and unilateral optic nerve transected macaque monkeys using diffusion tensor imaging (DTI). Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Group A served as a control group, and Group B underwent unilateral (right eye) optic nerve transection to produce monocular blindness. Sixteen months (Group B and thirty-two months (Group B) after optic nerve transection, diffusion tensor imaging was performed on all monkeys. Then, we compared fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in bilateral optic tracts between Group A and Group B and between Group B and Group B. In both Group B and Group B, when compared with normal monkeys in Group A, FA was decreased and MD, AD and RD were increased in the bilateral optic tracts of monkeys with monocular blindness. Furthermore, compared with Group B, FA was reduced and MD, AD, RD were more obviously increased in the bilateral optic tracts of Group B, and noticeable differences in MD, AD and RD were found between the left and right optic tracts in group B. We believe that the results of this study would be helpful in investigation of the histological abnormalities of the integrity damage, axonal degeneration and demyelination of optic tracts in macaque monkeys with monocular blindness by DTI parameters in noninvasively and quantitatively.
对于人类和非人灵长类动物，视觉剥夺后视觉通路白质纤维的改变已得到部分研究。然而，视神经横断后视束的变化尚未得到充分描述。在本研究中，我们试图使用扩散张量成像（DTI）研究正常和单侧视神经横断的猕猴视束之间的差异。将4只健康新生猕猴随机分为2组，每组2只。A组作为对照组，B组进行单侧（右眼）视神经横断以产生单眼失明。视神经横断后16个月（B组）和32个月（B组），对所有猕猴进行扩散张量成像。然后，我们比较了A组和B组之间以及B组和B组之间双侧视束的分数各向异性（FA）、平均扩散率（MD）、轴向扩散率（AD）和径向扩散率（RD）。在B组和B组中，与A组的正常猕猴相比，单眼失明猕猴双侧视束的FA降低，MD、AD和RD升高。此外，与B组相比，B组双侧视束的FA降低，MD、AD、RD升高更明显，且B组左右视束之间的MD、AD和RD存在显著差异。我们认为，本研究结果将有助于通过DTI参数以无创和定量的方式研究单眼失明猕猴视束完整性损伤、轴突变性和脱髓鞘的组织学异常。
