022 Re: Akbar - Inactivation of V-gated Sodium Channels

Leslie Samuel answers a question from Akbar about the inactive state of sodium channels. He explains the three states of a voltage-gated sodium channel: closed, open, and inactivated. Using a box analogy, he describes how the activation and inactivation gates function. The activation gate opens when the membrane potential becomes positive, and the inactivation gate closes automatically within milliseconds. The channel cannot be re-stimulated until it resets to the closed state. The difference between inactive and closed states is clarified, and viewers are encouraged to ask further questions.

What question did Akbar ask regarding the sodium channel?

• How does the sodium channel open?

• What is the difference between the inactive and closed states of the sodium channel?

• How does the sodium channel close?

• Why is the sodium channel important?

Which of the following is NOT a state of the sodium channel?

• Inactivated

• Open

• Deactivated

• Closed

What causes the activation gate of the sodium channel to open?

• A decrease in positive charge

• A decrease in membrane potential

• A buildup of positive charge

• An increase in negative charge

What happens to the inactivation gate after the activation gate opens?

• It closes after several seconds

• It opens wider

• It closes automatically within 0.5 to 1 millisecond

• It remains open indefinitely

How can the sodium channel be reset to the closed state?

• By increasing the positive charge inside the cell

• By decreasing the negative charge outside the cell

• By allowing potassium to rush out and make the cell more negative

• By increasing the membrane potential