Homoclinic bifurcations leading to the emergence of bursting oscillations in cell models V.N. Belykh, I.V. Belykh, M. Colding-Jørgensen and E. Mosekilde Eur. Phys. J. E, 3 3 (2000) 205-219 Published online: 15 November 2000 DOI: 10.1007/s101890070012