Neurite outgrowth guidance in vitro

Patterned substrates bound with a synthetic peptide were used to guide the outgrowth of hippocampal and cerebellar neurons in culture. Patterns of parallel lines were formed on glass substrates by coating the surfaces with an aminosilane chemical and irradiating them with deep UV light through a photomask. The patterns were then used to differentially attach a synthetic peptide derived from a neurite-outgrowth domain of laminin onto the surfaces. Hippocampal and cerebellar neurons were dissected from embryonic rats and grown on the substrates in chemically defined media. Both hippocampal and cerebellar neurons initially developed morphologies by reflecting the surface patterns in culture. With continued culture periods, the hippocampal neurons extended their longer neuritic processes mainly along the patterned lines, while their shorter processes showed random outgrowth. Our in vitro demonstration clearly shows an ability of growing neurites, putatively axons, for detecting a step gradient formed of substrate-bound laminin peptide. Substratum-guided axonal growth will be essential for the formation of well-organized small neuronal networks in culture