Statistical analysis of neuronal growth:: edge dynamics and the effect of a focused laser on growth cone motility
Statistical analysis of neuronal growth:: edge dynamics and the effect of a focused laser on growth cone motility
复制标题
DOI：
10.1088/1367-2630/9/11/426
复制
发表时间：
2007-11-30
影响因子：
3.3
通讯作者：
Kaes, J.
中科院分区：
文献类型：
--
作者：
Betz, T.;Koch, D.;Kaes, J.
神经元生长锥是神经元延伸尖端的小型动态结构，引导每个神经突延伸到其正确的伙伴细胞。为了达到指定的目标，生长锥以高精度和可靠性集成化学信号。这种信号检测的操作接近热噪声极限，因此不仅对于了解神经元生长，而且对于研究噪声影响下信号传导和信息处理的生物机制也具有很高的兴趣。为了进一步研究神经元的生长，使用位于生长锥前缘的聚焦激光来偏置生长方向，然而，这种影响的机制仍不清楚。我们对激光处理和控制生长锥的前沿动力学进行了详细的测量和分析。基于边缘运动测量，我们可以使用随机模型一致地描述神经元生长，该模型允许提取随机过程的双稳态电位和噪声强度。对不受激光影响的对照生长锥的研究揭示了噪声对生长锥整体活性的非线性依赖性。所提出的分析进一步量化了激光操纵的生长锥的边缘动力学。主动跟随激光的生长锥显示出双稳态电位在激光方向上的倾斜，有利于突出，但前缘生长速度没有显着变化。这与受激光影响的固定生长锥中观察到的潜在变化形成对比。在这里，激光不会倾斜潜在的形状，但可能通过增加肌动蛋白聚合速度来增加边缘速度。这些测量为生长锥突出和运动的动态提供了新的定量见解。
The neuronal growth cone is a small dynamic structure at the tip of neuronal extensions that guides each neurite extension to its correct partner cell. To reach the designated target, the growth cone integrates chemical signals with high accuracy and reliability. This signal detection operates close to the thermal noise limit and is, therefore of high interest not only to understand neuronal growth, but also to investigate the biological mechanisms of signalling and information processing under the influence of noise. To further investigate neuronal growth, a focused laser positioned at the leading edge of the growth cone is used to bias growth direction, however, the mechanisms of this influence are still unclear. We present a detailed measurement and analysis of the leading edge dynamics of laser treated and control growth cones. Based on the edge motility measurements, we can consistently describe neuronal growth with a stochastic model that allows a bistable potential and the noise intensity of the stochastic process to be extracted. The investigation of control growth cones that were not influenced by the laser reveals a nonlinear dependence of the noise on the overall activity of the growth cones. The presented analysis further quantifies the edge dynamics in growth cones that are manipulated by a laser. Growth cones that actively follow the laser show a tilt of the bistable potential in the direction of the laser to favour protrusions, but no significant changes in the leading edge growth velocity. This is in contrast to the potential changes observed in stationary growth cones that were influenced by the laser. Here, the laser does not tilt the potential shape, but increases the edge velocities, probably by an increase in actin polymerization velocity. These measurements provide new quantitative insight into the dynamics underlying growth cone protrusion and movement.