So it binds onto these channels, it causes these channels to open up and there is an influx of these sodium ions into the cell and that causes the process of depolarization of the membrane and that essentially creates an action potential. And this is what we mean by the signal transduction process. So our electron potential or our action potential, the electric signal is transduced. It's passed down from our presynaptic cell indirectly to the postsynaptic cell. Now, notice this electrical signal doesn't actually travel directly from the presynaptic cell to the post synaptic cell. Instead, we have this intermediate molecule, the neurotransmitter, that actually passes down that electrical signal.