being reinjected into the regions containing the folded singularities. This interplay between local and global mechanisms gives rise to [*mixed-mode oscillations*]{} (MMOs), which are periodic solutions of the dynamical system containing large and small amplitudes and a distinct separation between the two. These solutions may be characterized by their signatures, which are symbolic sequences of the form $L_1^{s_1}L_2^{s_2} \cdots$. This notation is used to indicate that a particular solution undergoes $L_1$ large oscillations, followed by $s_1$ small oscillations, followed by $L_2$ large oscillations, and so on. The distinction between ‘large’ and ‘small’ oscillations is dependent on the model. Nontrivial aperiodic solutions are referred to as [*chaotic MMOs*]{}, and may be characterized as limits of families of MMOs as the lengths of the signatures grow very large.

The classification of routes to MMOs with complicated signatures as well as chaotic MMOs continues to garner interest. Global bifurcations have been identified as natural starting points in this direction. Even so, the connection between these bifurcations and interactions of slow manifolds—which organize the global dynamics for small values of ${ \varepsilon}$—remains poorly understood. Period-doubling cascades, torus bifurcations,[@guckenheimer2008siam] and most recently, Shilnikov homoclinic bifurcations,[@guckenheimer2015] have been shown to produce MMOs with complex signatures. In 