Systems biological analysis of signal transduction in growth cones

我们开发了两种分析神经元生长锥行为的方法：基于FRET的细胞内第二信使（cAMP、cGMP和Ca^2+）成像技术和细胞内第二信使浓度和生长锥运动（伸长和收缩）的定量模拟技术。我们的主要成就如下。(1)新型的FRET传感器，同时荧光观察设备，和一个软件的线性分离荧光可视化细胞内第二信使串扰的开发。利用这种新的方法，我们成功地测量了细胞内的第二信使动力学在积极移动的生长锥详细。(2)我们建立了一个数学模型，预测了环核苷酸的浓度控制丝状伪足出现的频率和整个结构的转向。我们还开发了一个基于上述生化模型的空间模型。我们通过在反应空间中的格子表示的每个微区设置运动，重建了整个生长锥的转动现象。

We developed two methods for analyzing the behavior of the growth cones in neurons : FRET-based imaging technique for visualizing the intracellular second messengers(cAMP, cGMP and Ca^<2+>) and quantitative simulation technique for intracellular second messenger concentrations and mobility(elongation and contraction) of the growth cones. Our main achievements are followings.(1) New types of FRET sensors, simultaneous fluorescent observation equipment, and a software for linear separation of fluorescence were developed for visualizing intracellular second messenger cross-talk. Using this new method, we succeeded to measure the intracellular second messenger dynamics during actively mobile growth cones in detail.(2) We developed a mathematical model, and it predicted that the concentration of cyclic nucleotide controls the frequency of the emergency of filopodia, and the turning direction of whole structure. We also developed a spatial model based on the above biochemical model. We reconstructed the turning phenomenon of a whole growth cone by setting the movement at each microdomain, which is represented by the lattices in the reaction space.