Oh no! Not at all. They modulate amplitude, frequency, phase. They have recharge times and duty cycles and limits and hysteresis. Each neuron is like some FM radio station. Not remotely like binary.
If neurons only responded to each other at the min and max value (or a couple thresholds/ranges rather than strictly matching values), then it could be seen as binary. But they respond differently along the range of their inputs to produce a range of outputs, so not binary.