Before the action potential when the neuron is at rest, sodium channels are closed and don't allow sodium to pass-through. These channels are proteins.
What are sodium channels?
Sodium channels are specific channels composed of proteins that allow the passage of sodium ions in cells (e.g., neurons).
This passage is fundamental to generating a membrane potential during the transmission of electrical impulses.
When one action potential has been produced the depolarization of cells activates sodium channels.
Learn more about sodium channels here:
https://brainly.com/question/6316473
