Cytoskeletal Actin Dynamics are Involved in Pitch-Dependent Neurite Outgrowth on Bead Monolayers

Neurite outgrowth is an important preceding step for the development of nerve systems. Given that the in vivo environments of neurons consist of numerous hierarchical micro/nanotopographies, there have been many efforts to investigate the relationship between neuronal behaviors and surface topography. The acceleration of neurite outgrowth was recently reported on surfaces with a periodic nanotopography, but the biological mechanism has not yet been elucidated. In this work, the initial neurite development of hippocampal neurons on assembled silica beads with diameters ranging from 700 to 1800 nm was explored. The acceleration of neurite outgrowth increased with the surface-pitch size and leveled off after a pitch of 1 mm. Biochemical analysis indicated that cytoskeletal actin dynamics were primarily responsible for the recognition of surface topography. This work contributes to the emerging research field of topographical neurochemistry, as well as applied fields including neuroregeneration and neuroprosthetics.