Mechanical Computation in Neurons

Abstract

Motility is a major function of cells, playing a fundamental role in development and embryogenesis. Growth cones are the major motile structures usually located at the tip of neurites and are composed of a lamellipodium from which thin filopodia emerge. We have analyzed the kinetics and dynamics of growth cones from a computational point of view with the aim to understand two major issues: firstly, the strategy used by filopodia and lamellipodia during their exploration and navigation; secondly, which kind of mechanical problems neurons need to solve during their operation. Filopodia grow and retract following statistical patterns nearly optimal for an efficient exploration of the environment. This exploratory motion is at the basis of contact formation and the establishment of appropriate synaptic connections. Filopodia and lamellipodia can also avoid obstacles and occasionally lamellipodia can displace them. From this point of view, filopodial and lamellipodial motion can be described as a random process in which errors are corrected by efficient feed-back loops. We argue that neurons not only process sensory signals, but also solve mechanical problems throughout their entire lifespan, from the early stages of embryogenesis to adulthood.