Fig. 22

Robust heteroclinic cycle attractor for all-to-all coupled oscillatory Hodgkin–Huxley systems with delay synaptic coupling. The top panel shows synchronisation indices \(r_{ij}\) that only equal one when the systems i and j are synchronised while the bottom panel shows the action potentials \(v_{i}\) for the four oscillators; see [251] for more details. Observe that the mechanism of symmetry breaking and re-synchronisation of pairs is the same as in Fig. 21