激光陷阱对神经细胞生长方向的引导

Guiding neuronal growth direction with optical trap

提要神经系统的信息传递精确地依赖于轴突向其靶区组织的延伸。神经细胞生长锥沿一定路径生长,最后到达其正确的靶位。一般认为生长锥的生长可能被四种不同的机制所引导:接触吸引,化学吸引,接触排斥和化学排斥。与现存的方法不同,作者用特别设计的倒置式激光陷阱放在生长锥的前方来引导生长锥的生长方向。通过对生长锥施以持续的作用力,作者在实验上成功地引导了神经细胞生长锥的生长方向。控制神经生长一直是神经科学的基本目标,用激光陷阱引导神经生长可能会对神经回路的构建以及神经的再生起到非常重要的作用。

Neuronal growth cones navigate over long distances along specific pathways to find their correct targets. The prevailing opinion is that growth cones appear to be guided by four different mechanisms： contact attraction, chemoattraction, contact repulsion, and chemorepulsion. In contrast to existing methods, optical trap is used to guide neuronal growth in this paper. An intense light gradient near the focal region of a near-- infrared laser beam gives rise to forces that make possible optical trapping and manipulation of a variety of micron-sized objects. By controlling a persistent force exerted on the whole growth cone, the authors have shown experimentally that they can use optical trap to guide the growth direction of a neuron. In order to guide the neuronal growth direction, a self--contrived optical trap was placed just in front of a specific area of the edge of the cell＇s. The growth cone grew after the trap and turned to the direction the authors expected. Control over neuronal growth is a fundamental objective in neuroscience, and guiding neuronal growth with optical trap may be very important for the formation of neural circuits as well as nerve regeneration.