Molecular Substrates for Growing Neurons in Culture

Culturing neurons is an effective way to analyze the basic mechanisms that govern nervous system wiring. The choice of an appropriate molecular substrate is of prime importance to the main objective of the culture. We describe the preparation of basic 2D substrates, complex 2D substrates, and 3D substrates to culture neurons to evaluate neurotrophic activity of exogenous compounds. Complex 2D substrates allow analysis of guidance signals in a mixture of molecules mimicking the in vivo environment. In this case, the spatial distribution of the factors can be controlled by forming stripes (alternating substrates) or gradients. The use of 3D substrates is in our opinion the best choice to analyze the growth of axons from explants exposed to guidance signals. This method establishes standard and highly reproducible culture conditions for a given neuronal type.