Courte Josquin, Renault Renaud, Jan Audric, Viovy Jean-Louis, Peyrin Jean-Michel, Villard Catherine
Physico-Chimie Curie, Université PSL, CNRS, Institut Pierre-Gilles de Gennes pour la Microfluidique, Paris, France; Sorbonne Université, Institut Biologie Paris-Seine, CNRS, Inserm, Neuroscience Paris-Seine, Paris, France.
Physico-Chimie Curie, Université PSL, CNRS, Institut Pierre-Gilles de Gennes pour la Microfluidique, Paris, France.
Methods Cell Biol. 2018;148:71-95. doi: 10.1016/bs.mcb.2018.07.002. Epub 2018 Sep 14.
Microfluidic devices for controlling neuronal connectivity in vitro are extremely useful tools for deciphering pathological and physiological processes occurring in neuronal networks. These devices allow the connection between different neuronal populations located into separate culture chambers through axon-selective microchannels. In order to implement specific features of brain connectivity such as directionality, it is necessary to control axonal growth orientation in these devices. Among the various strategies proposed to achieve this goal, one of the most promising and easily reproducible is the use of asymmetric microchannels. We present here a general protocol and several guidelines for the design, production and testing of a new paradigm of asymmetric microchannels geometries based on a "return to sender" strategy. In this method, axons are either allowed to travel between the emitting and receiving chambers within straight microchannels (forward direction), or are rerouted toward their initial location through curved microchannels (reverse direction). We introduce variations of these "arches" microchannels and evaluate their respective axonal filtering capacities. Importantly, one of these variants presents an almost complete filtration of axonal growth in the non-permissive direction while allowing robust axonal invasion in the other one, with a selectivity ratio as high as 99.7%.
用于体外控制神经元连接性的微流控装置是用于解读神经元网络中发生的病理和生理过程的极其有用的工具。这些装置通过轴突选择性微通道实现位于单独培养室中的不同神经元群体之间的连接。为了实现大脑连接性的特定特征，如方向性，有必要在这些装置中控制轴突生长方向。在为实现这一目标而提出的各种策略中，最有前景且易于重现的策略之一是使用不对称微通道。我们在此展示了一种基于“原路返回”策略的不对称微通道几何形状新范式的设计、制作和测试的通用方案及若干指导原则。在这种方法中，轴突既可以在直的微通道内的发射和接收室之间行进（正向），也可以通过弯曲的微通道重新路由回到其初始位置（反向）。我们介绍了这些“拱形”微通道的变体，并评估了它们各自的轴突过滤能力。重要的是，这些变体之一在非允许方向上几乎完全过滤轴突生长，同时在另一个方向上允许强劲的轴突侵入，选择性比率高达99.7%。
