Acetylcholine (ACh) function
enables muscle action, learning, and memory. malfunction: with Alzheimer’s disease, ACh-producing neurons deteriorate.
Dopamine function
influences movement, learning, attention, and emotion. malfunction: oversupply linked to schizophrenia; undersupply linked to tremors and decreased mobility in Parkinson’s disease.
Serotonin function
affects mood, hunger, sleep, and arousal. malfunction: undersupply linked to depression; some drugs that raise serotonin levels are used to treat depression.
Norepinephrine function
helps control alertness and arousal. malfunction: undersupply can depress mood.
GABA (gamma-aminobutyric acid) function
a major inhibitory neurotransmitter. malfunction: undersupply linked to seizures, tremors, and insomnia.
Glutamate function
a major excitatory neurotransmitter; involved in memory. malfunction: oversupply can overstimulate the brain, producing migraines or seizures.
Endorphins function
neurotransmitters that influence the perception of pain or pleasure. malfunction: oversupply with opioid drugs can suppress the body’s natural endorphin supply.
Substance P function
involved in pain perception and immune response. malfunction: oversupply can lead to chronic pain.