Schematic of how a slope-threshold for spiking and an input-dependent membrane reset might underlie a dynamic spike-blocking state. A: Voltage response to a sustained input rises from 0, and has a slope (dashed line) that is sufficient to lead to a spike. At the end of the spike, the voltage is reset to 0.8, thereby making the shallow slope of the subsequent rise of voltage insufficient to produce a spike. B: Voltage response to an oscillating input rises from 0, and has a slope that is sufficient to lead to a spike. At the end of the spike, the voltage is reset to 0 because there is no input to the membrane. Therefore, the subsequent elevation of the input increases the membrane voltage with a sufficiently steep slope to produce another spike.