Figure 7. Mechanisms behind rebound bursting.

All panels show responses to strong hyperpolarizing synaptic input (50 synapses, activated with 10 ms intervals, during 300 ms). Rebound bursts were not elicited by P1 (A1) or P2 (A2), starting from their normal resting potentials of -63 mV and -69 mV, respectively. From a -57 mV holding potential, P1 (B1) elicited a rebound burst following hyperpolarization, while P2 did not (B2). Interchanging either the I_h conductance (C) or the Ca_T conductance (D) between P1 and P2, leaving all other parameters the same, reduced the rebound response in P1, and increased it in P2. Interchanging both the I_h and Ca_T conductances between P1 and P2, also interchanged their bursting abilities completely (E). The scale bar applies to all panels. When conductance values were changed, the resting potential was kept at the original level by small compensatory current injections.