MRI-based morphometric characterizations of sexual dimorphism of the cerebrum of ferrets (Mustela putorius)
MRI-based morphometric characterizations of sexual dimorphism of the cerebrum of ferrets (Mustela putorius)
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DOI：
10.1016/j.neuroimage.2013.06.024
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发表时间：
2013-12
期刊：
影响因子：
5.7
通讯作者：
K. Sawada;Miwa Horiuchi-Hirose;S. Saito;I. Aoki
中科院分区：
文献类型：
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作者：
K. Sawada;Miwa Horiuchi-Hirose;S. Saito;I. Aoki
本研究旨在使用高场MRI和基于MRI的形态测量学来表征年轻成年雪貂的脑形态及其性别二型性。离体短TR/TE（常规MRI的典型T1加权参数设置）和T2 W（长TR/TE）MRI具有7特斯拉的高空间分辨率，可以显示主要的皮层下和原皮层结构，即，尾状核、豆状核、杏仁核和海马体。特别是，嗅球的层状组织可通过短TR/TE-MRI识别。成年雪貂中观察到的初级和次级脑沟在短TR/TE-或T2 W-MRI上是可区分的，并且通过短TR/TE-MRI获得的3D渲染图像很好地再现了皮质表面形态。雌性动物的大脑体积显著低于雄性动物，这归因于雌性动物大脑皮质和皮质下白色物质的区域特异性体积减少。性别差异也被检测到，表现为整体减少的标准化信号比短TR/TE-MRI在所有的大脑结构检查女性比男性。另一方面，通过3D最大强度投影（MIP）显示了整个皮质的高和低短TR/TE-MRI强度横向区的交替阵列，这使人联想到功能性皮质区。短TR/TE-MRI的标准化信号比与髓鞘碱性蛋白免疫反应性纤维的密度呈负相关（男性，r =-0.440;女性，r =-0.481），而皮质中的T2 W-MRI则不相关。本研究结果表明，成年雪貂大脑的性别差异的特点是体积减少的大脑皮层和皮质下白色物质的女性，和整体减少的生理化学特征，通过短TR/TE-MRI，在女性。应该注意的是，基于短TR/TE-MRI的MIP在3D中描绘了与骨髓结构相关的功能性皮质区域。这种方法使得使用高场MRI对大脑皮层的功能组织及其异常进行常规调查成为可能。
The present study aimed to characterize cerebral morphology in young adult ferrets and its sexual dimorphism using high-field MRI and MRI-based morphometry.Ex vivoshort TR/TE (typical T1-weighted parameter setting for conventional MRI) and T2W (long TR/TE) MRI with high spatial resolution at 7-tesla could visualize major subcortical and archicortical structures, i.e., the caudate nucleus, lentiform nucleus, amygdala and hippocampus. In particular, laminar organization of the olfactory bulb was identifiable by short TR/TE-MRI. The primary and secondary sulci observable in the adult ferret were distinguishable on either short TR/TE- or T2W-MRI, and the cortical surface morphology was reproduced well by 3D-rendered images obtained by short TR/TE-MRI. The cerebrum had a significantly lower volume in females than in males, which was attributed to region-specific volume reduction in the cerebral cortex and subcortical white matter in females. A sexual difference was also detected, manifested by an overall reduction in normalized signal ratios of short TR/TE-MRI in all cerebral structures examined in females than in males. On the other hand, an alternating array of higher and lower short TR/TE-MRI intensity transverse zones throughout the cortex, which was reminiscent of the functional cortical areas, was revealed by maximum intensity projection (MIP) in 3D. The normalized signal ratio of short TR/TE-MRI, but not T2W-MRI in the cortex, was negatively correlated with the density of myelin-basic protein immunoreactive fibers (males, r = − 0.440; females, r = − 0.481). The present results suggest that sexual differences in the adult ferret cerebrum are characterized by reduced volumes of the cerebral cortex and subcortical white matter in females, and by overall reductions in physiochemical characteristics, as obtained by short TR/TE-MRI, in females. It should be noted that short TR/TE-MRI-based MIP delineated functional cortical areas related to myeloarchitecture in 3D. Such an approach makes possible conventional investigation of the functional organization of the cerebral cortex and its abnormalities using high-field MRI.