Mixed mode oscillations with gK = 4 nS, gA = 4 nS, and various values of C. (A) C = 0.05 pF is very small and the small amplitude oscillations are not visible. (B) When C is increased forty-fold (C = 2 pF) small oscillations become visible during the active phase, reflecting the twists near the folded node. Here we find smax = 5 plus one additional small oscillation at the beginning of the active phase. (C) With a larger conductance, C = 6 pF, the small oscillations (8 + 1) occur throughout the active phase. The predicted maximum number smax = 5 does not hold anymore because the conductance C, considered as a singular perturbation parameter, is too large.