Cavendish Laboratory, Department of Physics, University of Cambridge, 19 J.J. Thomson Avenue, Cambridge CB3 0HE, UK.
J Biomech. 2010 Nov 16;43(15):2986-92. doi: 10.1016/j.jbiomech.2010.07.002. Epub 2010 Jul 24.
The mechanical properties of tissues are increasingly recognized as important cues for cell physiology and pathology. Nevertheless, there is a sparsity of quantitative, high-resolution data on mechanical properties of specific tissues. This is especially true for the central nervous system (CNS), which poses particular difficulties in terms of preparation and measurement. We have prepared thin slices of brain tissue suited for indentation measurements on the micrometer scale in a near-native state. Using a scanning force microscope with a spherical indenter of radius ∼20μm we have mapped the effective elastic modulus of rat cerebellum with a spatial resolution of 100μm. We found significant differences between white and gray matter, having effective elastic moduli of K=294±74 and 454±53Pa, respectively, at 3μm indentation depth (n(g)=245, n(w)=150 in four animals, p<0.05; errors are SD). In contrast to many other measurements on larger length scales, our results were constant for indentation depths of 2-4μm indicating a regime of linear effective elastic modulus. These data, assessed with a direct mechanical measurement, provide reliable high-resolution information and serve as a quantitative basis for further neuromechanical investigations on the mechanical properties of developing, adult and damaged CNS tissue.
组织的力学性质越来越被认为是细胞生理学和病理学的重要线索。然而，关于特定组织力学性质的定量、高分辨率数据仍然很少。这对于中枢神经系统（CNS）尤其如此，因为在准备和测量方面存在特殊的困难。我们已经制备了适合在近天然状态下进行微米级压痕测量的脑组织薄片。我们使用具有半径约为 20μm 的球形压头的扫描力显微镜，以 100μm 的空间分辨率绘制了大鼠小脑的有效弹性模量图。我们发现白质和灰质之间存在显著差异，在 3μm 的压痕深度处，有效弹性模量分别为 K=294±74 和 454±53Pa（n(g)=245，n(w)=150，在四只动物中，p<0.05；误差为 SD）。与许多其他较大长度尺度上的测量不同，我们的结果对于 2-4μm 的压痕深度是恒定的，表明有效弹性模量处于线性范围。这些数据通过直接力学测量进行评估，为进一步研究发育、成年和受损中枢神经系统组织的力学性质提供了可靠的高分辨率信息和定量基础。
