And what time dependent means is they only open for a very small fraction of a second and they close immediately afterwards. So as soon as our threshold potential is reached, all these sodium voltage gated channels open up very quickly. And because they open up so quickly, we have the movement of the sodium channels from the outside of the sodium ions from the outside to the inside, down their electrochemical gradient. And as they move into the cell, they carry positive charge into the cell. And as they carry positive charge, that increases the positive charge on the inside of the cell compared to our outside. So we see this increase as shown by this curve.