University of Illinois at Urbana-Champaign, Department of Bioengineering, Cellular Neuroscience and Imaging Laboratory, Urbana, Illinois, United States.
University of Nebraska Medical Center, Munroe-Meyer Institute, Omaha, Nebraska, United States.
J Biomed Opt. 2017 Jun 1;22(6):66015. doi: 10.1117/1.JBO.22.6.066015.
Optimal growth as well as branching of axons and dendrites is critical for the nervous system function. Neuritic length, arborization, and growth rate determine the innervation properties of neurons and define each cell’s computational capability. Thus, to investigate the nervous system function, we need to develop methods and instrumentation techniques capable of quantifying various aspects of neural network formation: neuron process extension, retraction, stability, and branching. During the last three decades, fluorescence microscopy has yielded enormous advances in our understanding of neurobiology. While fluorescent markers provide valuable specificity to imaging, photobleaching, and photoxicity often limit the duration of the investigation. Here, we used spatial light interference microscopy (SLIM) to measure quantitatively neurite outgrowth as a function of cell confluence. Because it is label-free and nondestructive, SLIM allows for long-term investigation over many hours. We found that neurons exhibit a higher growth rate of neurite length in low-confluence versus medium- and high-confluence conditions. We believe this methodology will aid investigators in performing unbiased, nondestructive analysis of morphometric neuronal parameters.
轴突和树突的最佳生长以及分支对于神经系统功能至关重要。神经突的长度、分支和生长速度决定了神经元的神经支配特性，并定义了每个细胞的计算能力。因此，为了研究神经系统功能，我们需要开发能够量化神经网络形成的各个方面的方法和仪器技术：神经元过程的延伸、回缩、稳定性和分支。在过去的三十年中，荧光显微镜在我们对神经生物学的理解方面取得了巨大的进展。虽然荧光标记物为成像提供了有价值的特异性，但荧光漂白和光毒性常常限制了研究的持续时间。在这里，我们使用空间光干涉显微镜 (SLIM) 来定量测量细胞汇合度对神经突生长的影响。由于它是无标记且无损的，因此 SLIM 允许进行长达数小时的长期研究。我们发现，神经元在低汇合度条件下的神经突长度生长速度高于中高汇合度条件。我们相信这种方法将有助于研究人员对形态计量神经元参数进行无偏、无损的分析。
