Summary
Sodium channels open and the cell becomes positive, then potassium channels open to restore the negative interior.
In depth
Positive feedback drives the rising phase; inactivation and delayed K+ channels end it. The refractory period (absolute and relative) limits firing rate and ensures one-way propagation.
Sodium inactivation gate closes after about 1 ms; K+ channels reopen the membrane potential. The absolute refractory period limits maximum rates to about 500 to 1000 per second.
Example: lidocaine prevents depolarisation by blocking sodium channels.
Frequently asked questions
What is Depolarisation and Repolarisation?
Sodium channels open and the cell becomes positive, then potassium channels open to restore the negative interior.
Which area of biology covers Depolarisation and Repolarisation, and how advanced is it?
Depolarisation and Repolarisation is one of the 54 topics in Neuroscience. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Action Potential, Resting Membrane Potential, Voltage-Gated Ion Channels.
Can you give an example of Depolarisation and Repolarisation?
Tetrodotoxin from pufferfish blocks voltage-gated sodium channels and causes paralysis.
What should I learn before Depolarisation and Repolarisation?
Work through the Beginner topics in Neuroscience first, such as Nervous System, Neuron, Central and Peripheral Nervous Systems, then return to Depolarisation and Repolarisation. Intermediate topics assume the Beginner vocabulary.
What topics are related to Depolarisation and Repolarisation?
The closest topics to Depolarisation and Repolarisation are Action Potential, Resting Membrane Potential, Voltage-Gated Ion Channels, Synaptic Transmission. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Depolarisation and Repolarisation?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Depolarisation and Repolarisation. To practise the whole of Neuroscience, use the Neuroscience quiz.
How is Depolarisation and Repolarisation different from Action Potential?
Depolarisation and Repolarisation: Sodium channels open and the cell becomes positive, then potassium channels open to restore the negative interior. Action Potential: A rapid, all-or-none reversal of membrane potential that travels along an axon. Read both side by side and note what each one explains.
How should I study Depolarisation and Repolarisation step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Action Potential and explain the difference aloud. Finally, take the Neuroscience quiz and come back to this page for any question you miss.