Microtubules (MTs) organize intracellular transport, mechanics, and architecture, and their dysregulation in neurons is linked to aging and neurodegeneration. Despite extensive in vitro insight into MT regulators, we still lack a quantitative in vivo framework connecting nanoscale dynamics to micron-scale organization in dendrites. Here, we performed stochastic simulations of individual MTs evolving within reconstructed dendritic arbors. Our model couples dynamic-instability parameters to diffusion-limited tubulin supply and geometric confinement across the branched network. We predicted that morphology—via supply and confinement—sets local polymerization and catastrophe rates, yielding depth-dependent MT number and length. Simulations and model recapitulate recent experimental measurements, indicating that dendritic morphology establishes the baseline MT landscape. This quantitative bridge between molecular kinetics and geometry generates testable predictions for how growth, aging, or disease-related remodeling reprograms the neuronal MT network.
Thorens et al. (Sun,) studied this question.