Analysis of NMDA-dependent voltage bistability in thin dendritic compartments

We analyze the parameter ranges under which the voltage in a dendritic cable model exhibits bistability. We find (1) the magnitude of NMDA and GABA conductances limit the maximum cable diameter for which the system is bistable. For the investigated parameter ranges, the maximum diameter scales linearly with conductance. (2) NMDA current in the absence of GABA inhibition is not capable of generating bistability. (3) For small cable diameters (∼0.1 μm), the bistable equilibra of membrane potential occur at −33.3 and −79.2 mV, independent of the NMDA and GABA conductance.