“…The trajectories continue to remain in an O( ) neighborhood of the now repelling equilibrium curve for an O(1/ ) time, however, until the expansion governed by the now positive real parts of the eigenvalues of the linearization accumulates sufficiently to counter the earlier contraction. The time needed to escape from this curve can be calculated using a way-in way-out function (Diener, 1984;Neishtadt, 1987Neishtadt, , 1988. Interestingly, this delayed escape effect gives rise to elliptic bursting (Rinzel, 1987;Wang and Rinzel, 1995;Hoppensteadt and Izhikevich, 1997;Rubin and Terman, 2002) when the drift direction of the slow variable switches after escape and the periodic orbits born from the Hopf bifurcation have appropriate characteristics (Baer et al, 1989;Izhikevich, 2000;Kuske and Baer, 2002;Su et al, 2004).…”