Spatio-temporal Model

• Diffusion of cGMP and Ca2+ in the cytosol surrounding the discs.

• System of diffusion PDEs coupled via nonlinear BCs, in 2 and 3 dimensions.

• Finite Volume, explicit time-stepping, parallelized scheme.

• current: J = f(cG,Ca) at r=Rrod

• response = 1 – J / Jdark