FIGURE 5.

(A) Subcellular structures of neurons under cyclic stretch: a stress fiber in PC12 cell adhered to the substrate via a focal adhesion of receptor–ligand bonds. The evolution of the bond cluster is governed by the association and dissociation of receptor–ligand bonds. The stress fiber is assembled by monomers and can retrograde into monomers. (B) The viscoelastic model of contracting stress fiber described by a linear spring of stiffness k_f, a dashpot of viscous coefficient η_f in series, and a parallel module of active contraction force f₀.