Currents play critical roles in neurons. Direct observation of current flows in cells at nanometre dimensions and picoampere current resolution is still a daunting task. In this study, we investigated the current flows in hippocampal neurons, PC12 cells and astrocytes in response to voltages applied to the cell membranes using conductive atomic force microscopy (CAFM). The spines in the hippocampal neurons play crucial roles in nerve signal transfer. When the applied voltage was greater than 7.2 V, PC12 cells even show metallic nanowire‐like characteristics. Both the cell body and glial filaments of astrocytes yielded CAFM test results that reflect different electrical conductance. To our best knowledge, the electrical characteristics and current transport through components of cells (especially neurons) in response to an applied external voltage have been revealed for the first time at nanometre dimensions and picoampere current levels. We believe that such studies will pave new ways to study and model the electrical characteristics and physiological behaviours in cells and other biological samples.

中文翻译：

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通过导电原子力显微镜直接研究细胞中的电流传输

电流在神经元中起着关键作用。以纳米尺寸和皮安电流分辨率直接观察细胞中的电流仍然是一项艰巨的任务。在这项研究中，我们使用导电原子力显微镜 (CAFM) 研究了海马神经元、PC12 细胞和星形胶质细胞中的电流响应施加到细胞膜上的电压。海马神经元中的棘在神经信号传递中起着至关重要的作用。当外加电压大于 7.2 V 时，PC12 电池甚至表现出类似金属纳米线的特性。星形胶质细胞的细胞体和神经胶质丝都产生了反映不同电导率的 CAFM 测试结果。据我们所知，首次在纳米尺寸和皮安电流水平上揭示了响应施加的外部电压通过细胞（尤其是神经元）组件的电特性和电流传输。我们相信，此类研究将为研究和模拟细胞和其他生物样品中的电特性和生理行为铺平道路。