Bernstein Center for Computational Neuroscience, Humboldt University of Berlin, Berlin, Germany.
J Neurophysiol. 2010 Mar;103(3):1696-704. doi: 10.1152/jn.00421.2009. Epub 2009 Dec 2.
In the mammalian brain, many thousands of single-neuron recording studies have been performed but less than 10 single-cell stimulation studies. This paucity of single-cell stimulation data reflects a lack of easily applicable single-cell stimulation techniques. We provide a detailed description of the procedures involved in nanostimulation, a single-cell stimulation method derived from the juxtacellular labeling technique. Nanostimulation is easy to apply and can be directed to a wide variety of identifiable neurons in anesthetized and awake animals. We describe the recording approach and the parameters of the electric configuration underlying nanostimulation. We use glass pipettes with a DC resistance of 4-7 Mohms. Obtaining the juxtacellular configuration requires a close contact between pipette tip and neuron and is associated with a several-fold increase in resistance to values > or = 20 Mohms. The recorded action potential (AP) amplitude grows to > or = 2 mV, and neurons can be activated with currents in the nanoampere range--hence the term nanostimulation. While exact AP timing has not been achieved, AP frequency and AP number can be parametrically controlled. We demonstrate that nanostimulation can also be used to selectively inhibit sensory responses in identifiable neurons. Nanostimulation is biophysically similar to electroporation, and based on this assumption, we argue that nanostimulation operates on membranes in the micrometer area directly below the pipette tip, where membrane pores are induced by high transmembrane voltage. There is strong evidence to suggest that nanostimulation selectively activates single neurons and that the evoked effects are cell-specific. Nanostimulation therefore holds great potential for elucidating how single neurons contribute to behavior.
在哺乳动物大脑中，已经进行了数千项单细胞记录研究，但单细胞刺激研究不到 10 项。这种单细胞刺激数据的缺乏反映了缺乏易于应用的单细胞刺激技术。我们提供了一种源自细胞外标记技术的单细胞刺激方法——纳米刺激的详细描述。纳米刺激易于应用，可以在麻醉和清醒动物中靶向各种可识别的神经元。我们描述了记录方法和纳米刺激下的电配置参数。我们使用直流电阻为 4-7 Mohm 的玻璃吸管。获得细胞外配置需要吸管尖端与神经元的紧密接触，并与电阻增加几倍有关，电阻值>或= 20 Mohm。记录的动作电位（AP）幅度增加到>或= 2 mV，神经元可以用纳安范围内的电流激活-因此称为纳米刺激。虽然无法精确获得 AP 定时，但可以对 AP 频率和 AP 数量进行参数控制。我们证明纳米刺激也可用于选择性抑制可识别神经元的感觉反应。纳米刺激在生物物理上与电穿孔相似，基于这一假设，我们认为纳米刺激作用于吸管尖端下方微米区域的膜上，通过跨膜电压诱导膜孔。有强有力的证据表明，纳米刺激选择性地激活单个神经元，并且诱发的效应是细胞特异性的。因此，纳米刺激在阐明单个神经元如何对行为做出贡献方面具有巨大的潜力。
