Figure 3. Slow activating regenerative Ca²⁺ release dependence on the timing of PF-CF inputs.

A. Simulation results by Doi et al. [39] on Ca²⁺ activations at conjunctive PF-CF inputs with various intervals between the PF input and CF input. The PF input is delivered at 0 ms, indicated by the five vertical lines in panel A and a vertical gray bar in panel C. CF signal is given at −200∼+400 ms, as indicated by the single diagonal line. B. IP3 time courses in response to the various PF-CF inputs. Note that the IP3 profiles are almost identical regardless of the timing of PF-CF inputs or even for PF input alone. C. Our new model generates profiles of calcium activation similar to the model in A. D. Simulation by our model of IP3 activation at PF input. The new model adopts the results in panel B and uses just one IP3 activation profile (similar to PF alone in panel B) in generating the various Ca²⁺ profiles at various timing of PF-CF inputs in C. Panels A and B are from Doi et al. [39], with permission, copyright (2005) by the Society for Neuroscience.