Residual stress in the adult mouse brain.
Residual stress in the adult mouse brain.
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DOI：
10.1007/s10237-008-0131-4
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发表时间：
2009-08
影响因子：
3.5
通讯作者：
Taber LA
中科院分区：
文献类型：
--
作者：
Xu G;Bayly PV;Taber LA
这项工作提供了直接证据，证明在成熟小鼠大脑的白质中存在持续的张应力。这一发现对大脑发育的机制有重要的影响，因为神经轴突的紧张被假设为驱动人类大脑中的皮质折叠。此外，需要残馀应力的知识才能完全理解创伤性脑损伤背后的机制以及由于衰老和疾病而导致的机械性能变化。为了估计大脑中的残余应力，我们对500μm厚的新鲜成年小鼠脑冠状切片进行了一系列解剖实验，并为这些实验建立了有限元模型。径向切割要么切入皮质灰质，要么穿过皮质和由平行神经轴突组成的下层白质束。皮质灰质的伤口没有打开，但穿过两层的伤口始终在伤口穿过白质的地方打开。我们推测，在大脑冠状平面上，大脑白质在周向上处于相当大的张力中，与大多数神经纤维平行，而大脑皮质灰质处于压缩状态。模型表明，切割后观察到的变形可能是由灰质比白质更多的生长引起的，白质中的拉应力估计在100-1000帕左右。
This work provides direct evidence that sustained tensile stress exists in white matter of the mature mouse brain. This finding has important implications for the mechanisms of brain development, as tension in neural axons has been hypothesized to drive cortical folding in the human brain. In addition, knowledge of residual stress is required to fully understand the mechanisms behind traumatic brain injury and changes in mechanical properties due to aging and disease. To estimate residual stress in the brain, we performed serial dissection experiments on 500-μm thick coronal slices from fresh adult mouse brains and developed finite element models for these experiments. Radial cuts were made either into cortical gray matter, or through the cortex and the underlying white matter tract composed of parallel neural axons. Cuts into cortical gray matter did not open, but cuts through both layers consistently opened at the point where the cut crossed the white matter. We infer that the cerebral white matter is under considerable tension in the circumferential direction in the coronal cerebral plane, parallel to most of the neural fibers, while the cerebral cortical gray matter is in compression. The models show that the observed deformation after cutting can be caused by more growth in the gray matter than in the white matter, with the estimated tensile stress in the white matter being on the order of 100–1,000 Pa.