Neurobiology Sector, International School for Advanced Studies (SISSA), IT-34136 Trieste, Italy.
Sci Rep. 2011;1:153. doi: 10.1038/srep00153. Epub 2011 Nov 11.
We have used optical tweezers to identify the elementary events underlying force generation in neuronal lamellipodia. When an optically trapped bead seals on the lamellipodium membrane, Brownian fluctuations decrease revealing the underlying elementary events. The distribution of bead velocities has long tails with frequent large positive and negative values associated to forward and backward jumps occurring in 0.1-0.2 ms with varying amplitudes up to 20 nm. Jump frequency and amplitude are reduced when actin turnover is slowed down by the addition of 25 nM Jasplakinolide. When myosin II is inhibited by the addition of 20 μM Blebbistatin, jump frequency is reduced but to a lesser extent than by Jasplainolide. These jumps constitute the elementary events underlying force generation.
我们使用光镊来识别神经元片状伪足产生力的基本事件。当一个被光阱捕获的小球在片状伪足膜上密封时，布朗运动的波动减小，揭示了潜在的基本事件。小球速度的分布具有长尾，经常出现大的正负值，与在 0.1-0.2 毫秒内发生的前向和后向跳跃相关，幅度可达 20nm。当肌动蛋白周转率因添加 25 nM Jasplakinolide 而减慢时，跳跃频率和幅度都会降低。当肌球蛋白 II 被添加 20 μM Blebbistatin 抑制时，跳跃频率降低，但程度低于 Jasplainolide。这些跳跃构成了力产生的基本事件。
