Adaptive myelination theory reveals how brain rewires for synchrony and coordination

Researchers from the University of Nottingham have developed a new theoretical framework for understanding how adaptive conduction delays in neural networks regulate synchrony and coordination. Using the Haken Lighthouse model—an analytically tractable event-based description of neural dynamics—the team first analyzed networks with fixed delays, deriving self-consistency conditions for phase-locked states and a linear stability theory based on spike-time perturbations. They illustrated the approach for a delayed autapse, a reciprocally coupled two-cell network, and spatially structured rings with distance-dependent coupling and conduction delays, where circulant symmetry allowed stability decomposition into Fourier modes.

The key innovation is the introduction of an activity-dependent white matter plasticity rule in which myelination modulates axonal conduction speed, and hence communication delay. This creates a slow-fast system with state-dependent delays, where frozen phase-locked branches organize the adaptive dynamics. The plasticity rule selects commensurate delay–period relationships, providing a mechanism for the emergence of synchrony, other frequency-locked states, slow switching between competing phase-locked patterns, and the organization of heterogeneous delays into discrete delay–period classes. Direct simulations of the event-driven network support the analytical predictions and illustrate how adaptive conduction can reshape the attractor structure and generate long-timescale transitions. The work offers a tractable mathematical framework for studying how activity-dependent myelination may regulate temporal coordination in spiking neural systems.