Synaptic transmission is how a nerve impulse passes from one neuron to another:

1. Impulse reaches the axon terminal.
2. Voltage-gated Ca²⁺ channels open - Ca²⁺ enters the neuron.
3. Synaptic vesicles release neurotransmitters (like acetylcholine) into the synaptic cleft.
4. Neurotransmitters bind to receptors on the postsynaptic neuron.
5. Ion channels open - depolarisation occurs - new action potential is generated.
6. Neurotransmitters are broken down by enzymes or reabsorbed (reuptake).

Key Points:

• Chemical synapses are slower than electrical synapses but allow integration and regulation of signals
• Neurotransmitters determine whether the next neuron is excited or inhibited.