Fig. 1.

Proposed principle of activity-dependent plastic myelination in a network of neural oscillators. In our brain network model, oligodendrocyte glial cells (depicted here as small solid circles next to network connections) mediate plastic changes in axonal conduction as a function of the phase offset between pairs of connected oscillatory network nodes (depicted as large circles). If the phases of those oscillatory nodes are distributed randomly, the network is said to be in an incoherent state, and the associated phase differences trigger corrections in conduction velocity. Local phases (illustrated as rotating angles inside the large circles) dictate the magnitude of the changes in conduction velocity. If the phase offset between two connected networks is negative, the phase lag yields a stabilization of myelin and thus, an increase in conduction velocity. In addition to stabilization, a negative term tunes down the conduction velocity to model the metabolic cost associated with maintaining myelinated axons.