Langmuir. 2019 Aug 20;35(33):10965-10976. doi: 10.1021/acs.langmuir.9b01651. Epub 2019 Aug 9.
Neurons change their growth dynamics and mechanical properties in response to external stimuli such as stiffness of the local microenvironment, ambient temperature, and biochemical or geometrical guidance cues. Here we use combined atomic force microscopy (AFM) and fluorescence microscopy experiments to investigate the relationship between external temperature, soma volume, and elastic modulus for cortical neurons. We measure how changes in ambient temperature affect the volume and the mechanical properties of neuronal cells at both the bulk (elastic modulus) and local (elasticity maps) levels. The experimental data demonstrate that both the volume and the elastic modulus of the neuron soma vary with changes in temperature. Our results show a decrease by a factor of 2 in the soma elastic modulus as the ambient temperature increases from room (25 °C) to physiological (37 °C) temperature, while the volume of the soma increases by a factor of 1.3 during the same temperature sweep. Using high-resolution AFM force mapping, we measure the temperature-induced variations within different regions of the elasticity maps (low and high values of elastic modulus) and correlate these variations with the dynamics of cytoskeleton components and molecular motors. We quantify the change in soma volume with temperature and propose a simple theoretical model that relates this change with variations in soma elastic modulus. These results have significant implications for understanding neuronal development and functions, as ambient temperature, cytoskeletal dynamics, and cellular volume may change with variations in physiological conditions, for example, during tissue compression and infections as well as during cell manipulation and tissue regeneration .
神经元会根据外部刺激改变其生长动态和力学特性，例如局部微环境的刚度、环境温度以及生化或几何导向线索。在这里，我们使用原子力显微镜 (AFM) 和荧光显微镜实验来研究外部温度、细胞体体积和皮质神经元弹性模量之间的关系。我们测量环境温度变化如何影响神经元细胞在整体（弹性模量）和局部（弹性图谱）水平上的体积和力学特性。实验数据表明，神经元细胞体的体积和弹性模量都随温度变化而变化。我们的结果表明，随着环境温度从室温（25°C）升高到生理温度（37°C），细胞体的弹性模量降低了一个因子 2，而细胞体的体积在相同的温度扫描中增加了一个因子 1.3。使用高分辨率 AFM 力映射，我们测量了弹性图谱（弹性模量低值和高值）内不同区域的温度诱导变化，并将这些变化与细胞骨架成分和分子马达的动力学相关联。我们量化了细胞体体积随温度的变化，并提出了一个简单的理论模型，将这种变化与细胞体弹性模量的变化联系起来。这些结果对于理解神经元的发育和功能具有重要意义，因为环境温度、细胞骨架动力学和细胞体积可能会随着生理条件的变化而变化，例如在组织压缩和感染期间，以及在细胞操作和组织再生期间。
