The neuron and the action potential
Shows how a signal travels within one neuron, ending at the terminal where the synapse begins.
Where this fitsConnects to 1 · Unlocks 1
- Connects to
- Where drugs act: the brain's regions — Regions are made of billions of these cells.
- Unlocks
- The synapse: release, binding and termination — When the action potential reaches the terminal, the synapse takes over.
Walk through
Inputs arrive at the dendrites
Dendrites receive signals from other neurons. Each input is excitatory or inhibitory, depending on which ions flow in or out.
Analogy and worked example
Analogy: A line of dominoes: tipping the first one either knocks it over completely or not at all, and each falling domino tips the next one. A harder push doesn't make a bigger domino fall — you'd need more pushes, more often.
A neuron receives mostly inhibitory input. What happens to its firing?
- Inhibitory inputs push the neuron's voltage away from threshold.
Tip: the ← and → keys move through the lesson.
Full lesson: Neuron organization and relational terminology · Action potentials