3. What Really Travels Down the Axon?
Aug 24, 2026·
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1 min read
Xander Chu

Key Question
When a neuron fires, what actually travels down the axon?
What You’ll Learn
- What an action potential is
- Why individual ions do not travel from one end of the axon to the other
- How one region of membrane influences the next
- How depolarisation propagates along an axon
- Why the process resembles a relay
Key Takeaway
An action potential is not a group of ions racing down the entire axon.
Instead, changes in membrane voltage trigger neighbouring regions of membrane in sequence.
Next
Continue to Why Doesn’t the Action Potential Go Backwards?

Authors
Xander Chu
(they/them)
Founder, XC Psych
Psychology student at UNSW exploring psychology and neurobiology from first principles, with a background in data science, machine learning, software engineering, and tennis coaching.
