A developmental stretch-and-fill process that optimises dendritic wiring

Abstract

AbstractThe way in which dendrites spread within neural tissue determines the resulting circuit connectivity and computation. However, a general theory describing the dynamics of this growth process does not exist. Here we obtain the first time-lapse reconstructions of neurons in living fly larvae over the entirety of their developmental stages. We show that these neurons expand in a remarkably regular stretching process that conserves their shape. Newly available space is filled optimally, a direct consequence of constraining the total amount of dendritic cable. We derive a mathematical model that predicts one time point from the previous and use this model to predict dendrite morphology of other cell types and species. In summary, we formulate a novel theory of dendrite growth based on detailed developmental experimental data that optimises wiring and space filling and serves as a basis to better understand aspects of coverage and connectivity for neural circuit formation.In briefWe derive a detailed mathematical model that describes long-term time-lapse data of growing dendrites; it optimises total wiring and space-filling.HighlightsDendrite growth iterations guarantee optimal wiring at each iteration.Optimal wiring guarantees optimal space filling.The growth rule from fly predicts dendrites of other cell types and species.Fly neurons stretch-and-fill target area with precise scaling relations.Phase transition of growth process between fly embryo and larval stages.