Final answer:
Neurotransmitters can have either an excitatory effect or an inhibitory effect on the postsynaptic neuron. Excitatory neurotransmitters promote the generation of action potentials, while inhibitory neurotransmitters inhibit or prevent the generation of action potentials.
Step-by-step explanation:
The statement 'All neurotransmitters have an excitatory effect' is False. Neurotransmitters can have either an excitatory effect or an inhibitory effect on the postsynaptic neuron. Excitatory neurotransmitters promote the generation of action potentials, while inhibitory neurotransmitters inhibit or prevent the generation of action potentials.
Examples of excitatory neurotransmitters include glutamate and acetylcholine, which increase the likelihood of an action potential occurring. On the other hand, examples of inhibitory neurotransmitters include gamma-aminobutyric acid (GABA) and glycine, which decrease the likelihood of an action potential occurring.
In summary, not all neurotransmitters have an excitatory effect. Some neurotransmitters can have an inhibitory effect on the postsynaptic neuron.
Learn more about neurotransmitters