Neurotransmitters

Acetylcholine (ACh)

Excitatory or inhibitory; involved in arousal, attention, memory, and controls muscle contractions

Dopamine (DA)

Excitatory or inhibitory; involved in control of movement and sensations of pleasure

Serotonin (5-HT)

Excitatory or inhibitory; involved in sleep, mood, anxiety, and appetite

Endorphins

Inhibitory neural regulators; involved in pain relief

Norepinephrine (NE)

Mainly excitatory; involved in arousal and mood

Glutamate

Major excitatory neurotransmitter; involved in learning, memory formation, nervous system development, and synaptic plasticity

Gamma-aminobutyric acid (GABA)

Major inhibitory neurotransmitter; involved in sleep and inhibits movement