Big Idea 3.E
How do neurons work?
The axon of a neuron generates action potentials. This causes sodium channels to open and sodium ions to flood into the cell, down the concentration gradient. In response, potassium channels open and potassium ions flood out of the cell. This rapid movement of ions reverses the polarity of the membrane is called an action potential.
The sodium-potassium pump restores the membrane to its original polarized condition by pumping sodium and potassium ions back to their original position.
At the synapse, the impulse's electrical signal is converted into a chemical signal by releasing neurotransmitters across the synaptic cleft. When the transmitters bind to the postsynaptic receptor on the other side of the synapse, the signal is switched back into an electrical form, as charged ions flow into or out of the postsynaptic neuron.