Chemical synapse.

1. Voltage-gated Ca²⁺ channels in the presynaptic membrane open in response to an action potential.

2. Ca²⁺ ions flow in.

3. Synaptic vesicles fuse with presynaptic membrane of the synaptic terminal, releasing neurotransmitters.

4. Neurotransmitters diffuse across synaptic cleft and bind to ligand-gated channels in the postsynaptic membrane.

5. Ions flow in and generate a postsynaptic potential.

6. Neurotransmitters release from channels, which close.

Review: