Computing with the Cytoskeleton: A Problem of Scale
Microtubules and actin filaments are dynamic fibres constituting the skeleton of living cells. They show seemingly computational behaviours. Indeed, depending on conditions of reaction, they self-organise into temporal and/or spatial morphologies in vitro and act as micro-machine processors and actuators in living cells. Other systems – such as the bacterium-actin system – exist that ‘know‘ how to re-use the cytoskeleton for their own use (e.g. propulsion inside the cell). We discuss here about the possible reuse of the cytoskeleton for constructing fibrillar-based computational systems. I analyze particularly the possible existence of computational events based on ‘chemical collisions’ between microtubules. A molecular model of microtubule disassembly has been developed to verify that heterogeneities of composition and/or concentration of the chemical medium can form from shrinking microtubules and persist. They could serve as an efficient communication channel between fibrillar agents. Numerical simulations show that only very weak heterogeneities of composition form around the microtubule ends. However, the model predicts that they are notable when produced by arrays of numerous fibres such as microtubule arrays or comets of actin.