How Neurotransmitters Trigger or Block Signals

Neurotransmitters can either trigger or block signals at a chemical synapse. When an action potential reaches the presynaptic axon terminal, it causes the neuron to release neurotransmitters into the synaptic cleft. The released molecule then binds to specific receptors on the postsynaptic cell membrane.

Neurotransmitters released by a presynaptic neuron can be excitatory or inhibitory.

Excitatory neurotransmitters, such as acetylcholine and glutamate increase the chance of generating an action potential in the postsynaptic cell. 

The binding of these neurotransmitters on the ion channel receptors of the postsynaptic cell triggers ...