Bistable Dynamics Underlying Excitability of Ion Homeostasis in Neuron Models

doi:10.1371/journal.pcbi.1003551

Bistable Dynamics Underlying Excitability of Ion Homeostasis in Neuron Models

Figure 8

Two–parameter continuations of the fixed point bifurcations of Fig. 2.

In the left plot the dimensionless surface size parameter is varied, in the right plot the extracellular volume fraction is changed. The insets show the LP1 curves that mark the minimal physiological pump rate. The pump rates for which the system is bistable range from the LP1 to the HB3. The HB3 pump rate is required to repolarize a neuron that is in the depolarized equilibrium. The parameter (left plot plus inset) almost does not change the stability of the system, but (right plot) reduces the recovery pump rate significantly. The inset shows that the minimal physiological pump rate is much less affected. In each plot and inset the standard parameter value is indicated by the light–blue vertical line.

doi: https://doi.org/10.1371/journal.pcbi.1003551.g008