Therefore, the slope is the constant. More specifically, it is 58. This was covered during my lectures on ion channels. The equilibrium potential of the channel is point where no current is being passed, even if the channel is open. This was covered during my lectures on synapses and synaptic transmission.
Action potentials are only there to open voltage-gated calcium channels and allow calcium influx.
During synaptic transmission, a presynaptic influx of calcium causes release of neurotransmitter. This produces a higher concentration of calcium presynaptically, a greater release of neurotransmitter and a greater response postsynaptically. Therefore, only Time Constant is affected by Membrane Capacitance. This question required some research and thought. NMDA will not open due to its voltage-dependent block.