Acetylcholine

• Muscle action• Learning/Memory

• Decreased levels associated with Alzheimer disease

Dopamine

• Movement• Learning, attention• Emotion

• Excess associated with schizophrenia

• Decreased levels associated with Parkinson Disease

Serotonin

• Mood, hunger, sleep, arousal

• Decreased levels associated with depression

Norepinephrine

• Helps control alertness/arousal

• Decreased levels associated with depression

GABA

• “gamma-aminobutyric acid”

• Major inhibitory neurotransmitter

• Decreased levels associated with seizures, tremors, and insomnia

Glutamate

• Major excitatory neurotransmitter• Involved in memory

• Excess associated with overstimulation, seizures, and migraine headaches

Endorphins

• Released in response to pain and exercise

• Basis for ‘runner’s high’• Prescription narcotics are potent agonists

Divisions of the

Human Nervous

System