Weak hydrostatic forces in far-scanning ion conductance microscopy used to guide neuronal growth cones
Weak hydrostatic forces in far-scanning ion conductance microscopy used to guide neuronal growth cones
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DOI：
10.1016/j.neures.2010.11.009
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发表时间：
2011-03-01
影响因子：
2.9
通讯作者：
Ascoli, Cesare
中科院分区：
文献类型：
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作者：
Pellegrino, Mario;Orsini, Paolo;Ascoli, Cesare
扫描离子电导显微镜(SICM)目前用于活细胞的高分辨率形貌成像。最近，它也被用作向细胞传递刺激的工具。在这项工作中，我们研究了在SICM操作过程中吸管尖端与样品之间发生的机械相互作用。为此，我们建立了一种将SICM和原子力显微镜(AFM)相结合的装置，其中AFM悬臂取代了样品。我们的数据表明，在远扫描模式下，当电流减小值小于2%时，只要填充移液管的电解液水平等于毛细管张力所确定的水平，就不能检测到力。即使在远扫描模式下，与此值不同的填充水平也决定了静液压力、通过吸管尖端的流量和可检测到的力。这些力的绝对值取决于吸管尖端的大小。因此，当使用SICM进行细胞成像时，一个可能的陷阱是暗示了零力工作条件。然而，可以利用流体静力来传递微弱的机械刺激并引导神经元生长锥体。文中给出了这种方法有效性的证据。(C)2010年爱思唯尔爱尔兰有限公司和日本神经科学学会。版权所有。
Scanning ion conductance microscopy (SICM) is currently used for high resolution topographic imaging of living cells. Recently, it has been also employed as a tool to deliver stimuli to the cells. In this work we have investigated the mechanical interaction occurring between the pipette tip and the sample during SICM operation. For the purpose, we have built a setup combining SICM with atomic force microscopy (AFM), where the AFM cantilever replaces the sample. Our data indicate that, operating in far-scanning mode with current decrease values below 2%, no force can be detected, provided that the level of the electrolyte filling the pipette is equal to that determined by the capillary tension. A filling level different from this value determines a hydrostatic pressure, a flux through the pipette tip and detectable forces, even in far-scanning mode. The absolute value of these forces depends on the pipette tip size. Therefore, a possible pitfall when using SICM for cell imaging is to imply zero-force working conditions. However the hydrostatic forces can be exploited in order to deliver weak mechanical stimuli and guide neuronal growth cones. Evidences of the effectiveness of this approach are herein given. (C) 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.