Institute of Bio- and Nanosystems (IBN2), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Biomaterials. 2011 Mar;32(8):2070-6. doi: 10.1016/j.biomaterials.2010.11.036. Epub 2010 Dec 17.
Substrate-bound gradients expressed in numerous spatio-temporal patterns play a crucial role during the development of complex neural circuits. A deeper understanding of the axon guidance mechanism is provided by studying the effect of a defined substrate-bound cue on a confined neural network. In this study, we constructed a discontinuous substrate-bound gradient to control neuronal cell position, the path of neurite growth, and axon directionality. A variety of gradient patterns, with slight changes in slope, width, and length were designed and fabricated by microcontact printing using laminin/poly-l-lysine (PLL) or PLL alone. The gradients were tested for neurite growth and their impact on axon guidance of embryonic rat cortical neurons. The neurite length was determined and the axon was evaluated by Tau-1 immunostaining. We found that the microgradients of laminin/PLL and PLL directed neurons' adhesion, differentially controlled the neurite growth, and guided up to 84% of the axons. The effect of the protein micropattern on axon guidance and neurite growth depended on the protein and geometric parameters used. Our approach proved to be very successful in guiding axons of single multipolar neurons with very high efficiency. It could thereby be useful to engineer defined neural networks for analyzing signal processing of functional circuits, as well as to unravel fundamental questions of the axon guidance mechanism.
在复杂神经网络的发育过程中，大量具有时空图案的基质束缚梯度发挥着关键作用。通过研究特定的基质束缚线索对受限神经网络的影响，可以更深入地了解轴突导向机制。在这项研究中，我们构建了不连续的基质束缚梯度来控制神经元细胞的位置、轴突生长的路径和轴突的方向性。通过使用层粘连蛋白/聚-l-赖氨酸 (PLL) 或 PLL 单独进行微接触印刷，设计并制造了具有轻微斜率、宽度和长度变化的各种梯度图案。测试了这些梯度对胚胎大鼠皮质神经元突起生长及其对轴突导向的影响。通过 Tau-1 免疫染色确定了突起的长度，并评估了轴突。我们发现，层粘连蛋白/PLL 和 PLL 的微梯度指导神经元的黏附，差异控制着突起的生长，并引导了多达 84%的轴突。蛋白质微图案对轴突导向和突起生长的影响取决于所使用的蛋白质和几何参数。我们的方法在引导具有非常高效率的单个多极神经元的轴突方面非常成功。因此，它可能有助于构建用于分析功能电路信号处理的特定神经网络，以及揭示轴突导向机制的基本问题。
