  Realistic large-scale networks display an heterogeneous distribution of
connectivity weights, that might also randomly vary in time. We show that
depending on the level of heterogeneity in the connectivity coefficients,
different qualitative macroscopic and microscopic regimes emerge. We evidence
in particular generic transitions from stationary to perfectly periodic
phase-locked regimes as the disorder parameter is increased, both in a simple
model treated analytically and in a biologically relevant network made of
excitable cells.
