1. The heterogeneity model gLgL VLVL g Ca V Ca C VmVm C = g L (V m -V L )+g Ca (V m -V Ca ) dV dt g Ca = g Ca m 3 h g Ca (mS/cm 2 ) g L (mS/cm 2 ) dh dt h inf (Vm)-h = hh

3. Reconstructing the phase diagram

5. The line connecting the two cells crosses the oscillating zone. The combination of the average channel densities falls inside the oscillating or stable zone. g Ca (mS/cm 2 ) g L (mS/cm 2 )

9. 5 mV 100 ms Timing of neuronal output by subthreshold oscillations IV=I+II V=IV-III

10. The timing of neuronal output is frequency dependent