Investigation of the mechanism of contact guidance of neurite growth cones in magnetically-aligned collagen gels

We have studied the adhesion anisotropy hypothesis of neuronal contact guidance by culturing PC12 cells in magnetically-aligned collagen gels. Neurite contact guidance was compared between aligned collagen gels and gels aligned to the same degree but subsequently equilibrated in a solution of monoclonal anti-rat α1 integrin antibody that is known to inhibit rat PC12 neuritogenesis. Modulation of integrin binding would not affect the anisotropic mechanical properties of the aligned collagen network, but it would affect growth cone adhesion, which is anisotropic due to the aligned collagen fibrils. Contact guidance was quantified by measuring the length and orientation of neurite projection 48 hours after culture. We found no difference in the contact guidance response, implying that the contact guidance mechanism is not primarily due to anisotropic adhesion. Experiments are currently underway to investigate a mechanical anisotropy mechanism