Resumen: We characterize the systematic changes in the topological structure of chaotic attractors that occur as spike-adding and homoclinic bifurcations are encountered in the slow-fast dynamics of neuron models. This phenomenon is detailed in the simple Hindmarsh-Rose neuron model, where we show that the unstable periodic orbits appearing after each spike-adding bifurcation are associated with specific symbolic sequences in the canonical symbolic encoding of the dynamics of the system. This allows us to understand how these bifurcations modify the internal structure of the chaotic attractors. Idioma: Inglés DOI: 10.1209/0295-5075/109/20002 Año: 2015 Publicado en: Europhysics letters 109, 2 (2015), 20002 [6 pp.] ISSN: 0295-5075 Factor impacto JCR: 1.963 (2015) Categ. JCR: PHYSICS, MULTIDISCIPLINARY rank: 19 / 79 = 0.241 (2015) - Q1 - T1 Factor impacto SCIMAGO: 0.625 - Physics and Astronomy (miscellaneous) (Q2)