Parameter variation: membrane receptor activity. Simulation results showing how postsynaptic membrane receptor activity following neurotransmitter release is sensitive to an increase of the parameter from 6 (reference case, see Figure 4) to 60. This coefficient is relevant for the unbinding rate of the transmitter-channel complex. See legend of Figure 4 for details. The variation of one order of magnitude seems to not significantly alter the kinetics of the main opening channel mechanism, represented by O1 (compare the rightmost pictures of this figure and Figure 4).