Fig. 13

Computation of the lower attracting slow manifold \(S^{a}_{\varepsilon }\) of the Hodgkin–Huxley model (32) with \(\varepsilon =0.0083\) and \(I=9.74\). Panels (a) and (b) show two submanifolds of \(S^{a}_{\varepsilon }\) (red surfaces) together with their respective boundary conditions \(L^{a}_{1}\) and \(L^{a}_{2}\) (blue lines), and \(\varSigma ^{a}\) (blue planes); they are rendered from the orbit segments shown as thick curves (black and green, respectively). Panel (c) shows both submanifolds of \(S^{a}_{\varepsilon }\) together as a single surface