Synchronicity transitions determine coupling fluctuations in a model of coupled oscillators with plasticity

Sleep and rest, characterized by synchronized neuronal activity that emerges under large shifts in the excitation–inhibition balance, are crucial for synaptic reorganization in the brain. However, the network dynamics that permit rewiring without erasing stable connections remain unclear. To address this question, we extended a Kuramoto framework with excitation–inhibition balance by adding Hebbian and homeostatic plasticity. The resulting model showed that networks with robust inhibition consistently exhibited desynchronized dynamics and stable couplings. In contrast, networks with weaker inhibition exhibited a bistable regime, in which couplings of intermediate strengths fluctuated while strong couplings remained stable. These findings suggest that the dynamic interplay between network activity and plasticity selectively stabilizes stronger connections while permitting flexible reorganization of weaker ones, providing a potential mechanism for network reorganization during sleep and rest.