Li Yinyun, Brown Anthony, Jung Peter
Quantitative Biology Institute, Ohio University, Athens, OH 45701, USA.
Phys Biol. 2014 Apr;11(2):026001. doi: 10.1088/1478-3975/11/2/026001. Epub 2014 Mar 17.
Neurofilaments are transported along axons stochastically in a stop-and-go manner, cycling between brief bouts of rapid movement and pauses that can vary from seconds to hours in length. Presently the only way to analyze neurofilament pausing experimentally on both long and short time scales is the pulse-escape method. In this method, fluorescence photoactivation is used to mark a population of axonal neurofilaments and then the loss of fluorescence from the activated region due to neurofilament movement is monitored by time-lapse imaging. Here we develop a mathematical description of the pulse-escape kinetics in terms of the rate constants of a tested mathematical model and we show how this model can be used to characterize neurofilament transport kinetics from fluorescence photoactivation pulse-escape experiments. This combined experimental and computational approach is a powerful tool for the analysis of the moving and pausing behavior of neurofilaments in axons.
神经丝以随机的停停走走方式沿轴突运输，在快速运动的短暂发作和持续时间从几秒到几小时不等的停顿之间循环。目前，在长时间和短时间尺度上通过实验分析神经丝停顿的唯一方法是脉冲逃逸法。在这种方法中，荧光光激活用于标记一群轴突神经丝，然后通过延时成像监测由于神经丝移动导致的激活区域荧光损失。在这里，我们根据测试数学模型的速率常数对脉冲逃逸动力学进行了数学描述，并展示了该模型如何用于从荧光光激活脉冲逃逸实验中表征神经丝运输动力学。这种实验与计算相结合的方法是分析轴突中神经丝移动和停顿行为的有力工具。
