Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.
Eur J Neurosci. 2021 Feb;53(3):778-795. doi: 10.1111/ejn.15028. Epub 2020 Nov 21.
It is well established that early blindness results in behavioural adaptations. While the functional effects of visual deprivation have been well researched, anatomical studies are scarce. The aim of this study was to investigate whole brain structural plasticity in a mouse model of congenital blindness. Volumetric analyses were conducted on high-resolution MRI images and histological sections from the same brains. These morphometric measurements were compared between anophthalmic and sighted ZRDBA mice obtained by breeding ZRDCT and DBA mice. Results from MRI analyses using the Multiple Automatically Generated Templates (MAGeT) method showed smaller volume for the primary visual cortex and superior colliculi in anophthalmic compared with sighted mice. Deformation-based morphometry revealed smaller volumes within the dorsal lateral geniculate nuclei and the lateral secondary visual cortex and larger volumes within olfactory areas, piriform cortex, orbital areas and the amygdala, in anophthalmic compared with sighted mice. Histological analyses revealed a larger volume for the amygdala and smaller volume for the superior colliculi, primary visual cortex and medial secondary visual cortex, in anophthalmic compared with sighted mice. The absence of superficial visual layers of the superior colliculus and the thinner cortical layer IV of the primary and secondary visual cortices may explain the smaller volume of these areas, although this was observed in a limited sample. The present study shows large-scale brain plasticity in a mouse model of congenital blindness. In addition, the congruence of MRI and histological findings support the use of MRI to investigate structural brain plasticity in the mouse.
众所周知，早期失明会导致行为适应。虽然视觉剥夺的功能影响已经得到了充分的研究，但解剖学研究却很少。本研究旨在研究先天性失明小鼠模型中的全脑结构可塑性。对来自同一大脑的高分辨率 MRI 图像和组织学切片进行了体积分析。通过繁殖 ZRDCT 和 DBA 小鼠获得的无眼和有眼 ZRDBA 小鼠之间进行了这些形态测量比较。使用多自动生成模板（MAGeT）方法进行的 MRI 分析结果显示，无眼小鼠的初级视觉皮层和上丘体积小于有眼小鼠。变形形态测量显示，无眼小鼠的背外侧膝状体核和外侧次级视觉皮层的体积较小，而嗅觉区域、梨状皮层、眶区和杏仁核的体积较大。与有眼小鼠相比，无眼小鼠的杏仁核体积较大，上丘、初级视觉皮层和内侧次级视觉皮层体积较小。无眼小鼠上丘的浅层视觉层和初级及次级视觉皮层的 IV 层皮质厚度较小，可能导致这些区域的体积较小，但这种情况仅在有限的样本中观察到。本研究表明先天性失明小鼠模型存在大规模的大脑可塑性。此外，MRI 和组织学发现的一致性支持使用 MRI 研究小鼠的结构性大脑可塑性。
