We quantitatively analyzed, using laser scanning confocal microscopy, the three-dimensional structure of individual senile plaques in Alzheimer disease. We carried out the quantitative analysis using statistical methods to gain insights about the processes that govern A-beta peptide deposition. Our results show that plaques are complex porous structures with characteristic pore sizes. We interpret plaque morphology in the context of a new dynamical model based
on competing aggregation and disaggregation processes in kinetic steady-state equilibrium with an additional diffusion process allowing A-beta deposits to diffuse over the surface of plaques.