On the contrary, the sodium voltage gated on channels open up very, very quickly. And so that's exactly why we have this deep polarization period, a rapid increase to a positive value of that potential. So the opening of the voltage gated sodium channels leads to a rapid rise in the membrane potential. Now, although the voltage gated potassium channels are slow to open, they too begin to open. But they open very slowly. But after about one millisecond of the opening of these sodium voltage gate on channels, they begin to close as a result of the inactivation of this ball.