Pan Wen-Ju, Wu Guangyao, Li Chun-Xia, Lin Fuchun, Sun Junmo, Lei Hao
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academic of Sciences, Wuhan 430071, PR China.
Neuroimage. 2007 Aug 1;37(1):212-20. doi: 10.1016/j.neuroimage.2007.05.014. Epub 2007 May 18.
Many previous neuroimaging studies have shown that the early visual cortex of the early blind (EB) exhibits significant functional plasticity. However, only few previous studies have addressed the question whether or not such functional plasticity is accompanied by, and even related to, structural plasticity. In this study, we acquired high-resolution whole-brain anatomical magnetic resonance images form 14 Chinese EB adults, who lost sight before 6 years of age, and 16 age/gender-matched normal-sighted controls (SC), and compared pixel-by-pixel the gray matter (GM) and white matter (WM) volumes between the two groups with voxel-based morphometry. The results showed that, relative to the SC, the EB exhibits significantly reduced WM volumes in the optic tract and optic radiation and significant GM losses in the early visual cortex. The reduction of WM volume in the optic radiation of the EB was found be modulated by both the age at blindness onset and the duration of blindness. The reduction of GM volume in the early visual cortex of the EB appeared to be unaffected by the age at blindness onset. However, it was found in localized regions of the atrophic early visual cortex of the EB that the GM loss was progressive with aging and increasing duration of blindness. These results suggest that early visual deprivation induces significant structural plasticity in the optic pathway and early visual cortex of the EB, which likely occurs during both the critical period of early neurodevelopment and the course of persisted blindness later in life through activity-dependent mechanisms.
许多先前的神经影像学研究表明，早期失明者（EB）的早期视觉皮层表现出显著的功能可塑性。然而，以前只有少数研究探讨了这种功能可塑性是否伴随着甚至与结构可塑性相关的问题。在本研究中，我们采集了14名6岁前失明的中国成年EB者和16名年龄及性别匹配的视力正常对照者（SC）的高分辨率全脑解剖磁共振图像，并使用基于体素的形态学方法逐像素比较了两组之间的灰质（GM）和白质（WM）体积。结果显示，相对于SC，EB者的视束和视放射中的WM体积显著减少，早期视觉皮层中的GM显著丢失。发现EB者视放射中WM体积的减少受失明起始年龄和失明持续时间的调节。EB者早期视觉皮层中GM体积的减少似乎不受失明起始年龄的影响。然而，在EB者萎缩的早期视觉皮层的局部区域发现，GM丢失随着年龄增长和失明持续时间的增加而进展。这些结果表明，早期视觉剥夺在EB者的视路和早期视觉皮层中诱导了显著的结构可塑性，这可能在早期神经发育的关键期以及随后生命中持续失明的过程中通过活动依赖机制发生。
