Chaos in two heteroclinic cycles coupled with chemical synapses Alexander G. Korotkov, Evgeny A. Grines, Ekaterina V. Syundyukova, Elena V. Gubina and Tatiana A. Levanova Eur. Phys. J. Spec. Top., Publication ahead of print Published online: 11 June 2025 DOI: 10.1140/epjs/s11734-025-01723-8