Mechanical properties of dura mater from the rat brain and spinal cord
Mechanical properties of dura mater from the rat brain and spinal cord
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DOI：
10.1089/neu.2007.0348
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发表时间：
2008-01-01
影响因子：
4.2
通讯作者：
Shreiber, David I.
中科院分区：
文献类型：
--
作者：
Maikos, Jason T.;Elias, Ragi A. I.;Shreiber, David I.
硬脑膜是中枢神经系统 (CNS) 组织最外层和最坚固的脑膜层，充当大脑和脊髓的保护膜。在创伤性脑损伤和脊髓损伤的动物模型中，机械损伤通常直接传递到硬脑膜以损伤下面的组织。因此，包括硬脑膜机械性能的描述对于这些模型的生物力学分析至关重要。我们表征了大鼠大脑和脊髓硬脑膜在单轴张力下的机械反应。测试在低应变率（0.0014 sec(-1)）和高应变率（19.42 sec(-1)）下进行。大鼠颅硬脑膜和脊髓硬脑膜均表现出胶原软组织特有的非线性应力应变反应特征。与硬脑膜相比，硬脊膜中应力的非线性增加滞后。慢速数据符合一项奥格登超弹性本构定律，并且观察到刚度 G 和参数 α 存在显着差异，名义上引入了非线性。高应变率应力松弛测试进行至10%应变，保持10秒。该松弛符合四项 Prony 级数指数衰减。硬脑膜和硬脊膜表现出相似的整体松弛，但在 Prony 系列参数上的松弛分布上发现了显着差异，这表明硬脑膜往往松弛得更快。偏光显微镜显示硬脊膜的结构实体沿轴向排列，而颅骨硬脑膜并未表现出优先排列。这一点通过 Masson 的三色染色和 Verhoeff 的 Van Gieson 染色对胶原蛋白和弹性蛋白进行定性证实，这也表明硬脊膜的弹性蛋白含量高于硬脑膜。
The dura mater is the outermost and most substantial meningial layer of central nervous system (CNS) tissue that acts as a protective membrane for the brain and spinal cord. In animal models of traumatic brain injury and spinal cord injury, mechanical insults are often delivered directly to the dura to injure the underlying tissue. As such, including a description of the mechanical properties of dura mater is critical for biomechanical analyses of these models. We have characterized the mechanical response of dura mater from the rat brain and spinal cord in uniaxial tension. Testing was performed at low (0.0014 sec(-1)) and high (19.42 sec(-1)) strain rates. Both rat cranial dura and spinal dura demonstrated non-linear stress-strain responses characteristic of collagenous soft tissues. The non-linear increase in stress lagged in the spinal dura compared to the cranial dura. The slow rate data was fit to a one-term Ogden hyperelastic constitutive law, and significant differences were observed for the stiffness, G, and the parameter, alpha, which nominally introduces non-linearity. High strain rate stress-relaxation tests were performed to 10% strain, which was held for 10 sec. The relaxation was fit to a four-term Prony series exponential decay. Cranial dura and spinal dura demonstrated similar overall relaxation, but significant differences were identified in the distribution of the relaxation over the Prony series parameters, which demonstrated that cranial dura tended to relax faster. Polarized light microscopy revealed that the structural entities of spinal dura were aligned in the axial direction, whereas cranial dura did not demonstrate a preferential alignment. This was confirmed qualitatively with Masson's Tri-chrome and Verhoeff's Van Gieson staining for collagen and elastin, which also indicated greater elastin content for the spinal dura than for the cranial dura.