Fig. 1.

Structural and soluble cues directing axonal outgrowth along “living scaffolds”. (A) Axon growth is directed along existing axonal tracts (“pioneer” axons in development or tissue engineered axonal tracts in regeneration) due to a combination of a precise spatial presentation of cell-adhesion molecules (CAMs) and the intimate presentation of secreted chemotactic and neurotrophic factors. (B) Axon guidance may also progress along aligned astrocytic somata and processes, where the presentation and/or gradients of CAMS, extracellular matrix constituents, and secreted neurotrophic factors promote axon guidance. Similarly, “living scaffolds” may also be applied to facilitate and direct cell migration to reconstruct complex neural tissue structure (not shown).