We study the collective dynamics of an ensemble of coupled identical
FitzHugh--Nagumo elements in their excitable regime. We show that collective
firing, where all the elements perform their individual firing cycle
synchronously, can be induced by random changes in the interaction pattern.
Specifically, on a sparse evolving network where, at any time, each element is
connected with at most one partner, collective firing occurs for intermediate
values of the rewiring frequency. Thus, network dynamics can replace noise and
connectivity in inducing this kind of self-organised behaviour in highly
disconnected systems which, otherwise, wouldn't allow for the spreading of
coherent evolution.Comment: 5 pages, 5 figure
