Neurotransmitters & Hormones

neurotransmitter

a chemical messenger used to transmit messages between neurons

inhibitory neurotransmitter

prevents an action potential in a neuron, stopping the message (simple terms: tells neurons to stop or slow down)

excitatory neurotransmitter

encourages an action potential in a neuron, resulting in a message being sent (simple terms: tells neurons to GO)

acetylcholine

excitatory neurotransmitter that controls voluntary movement; controls memory formation and recall

deficit linked to Alzheimer’s (memory issues, tremors)

surplus linked to nerve spasms

dopamine

neurotransmitter that controls involuntary movement (muscle coordination); reward/pleasure chemical; can be inhibitory or excitatory

deficit linked to Parkinson’s

surplus linked to addiction and schizophrenia

endorphins

inhibitory neurotransmitters that are natural pain killers; can trigger the release of dopamine

deficits linked to chronic pain (e.g. recovering opioid addicts experience severe pain during withdrawal)

surplus linked to drug addiction (opiates in particular)

GABA/gamma-amino-butanoic-acid

most abundant inhibitory neurotransmitter; calms the nervous system down

deficits linked to anxiety

surplus linked to sleep disorders (e.g. narcolepsy)

glutamate

most abundant excitatory neurotransmitter; related to thinking and memory

deficit linked to depression (tired/numb/unmotivated feeling)

surplus linked to anxiety

norepinephrine

excitatory neurotransmitter related to alertness and memory formation

deficits linked to depression

surplus linked to high blood pressure and heart arrhythmias

serotonin

neurotransmitters that control mood/emotions, appetite, wakefulness, and sex drive; can be inhibitory or excitatory

deficits linked to depression (sadness, excessive sleeping)

surplus linked to mania (inability to sleep; usually seen in bipolar disorder)

substance P

excitatory neurotransmitter responsible for the perception of pain

deficits linked to impaired pain sensitivity

surplus linked to chronic pain (e.g. fibromyalgia)

hormone

a chemical messenger used by the endocrine system

adrenaline

hormone that facilitates responses to stressful or exciting situations

surplus linked to anxiety disorders

ghrelin

stimulates appetite; “hunger hormone”

deficits linked to unexpected weight loss

leptin

suppresses appetite; “full hormone”

deficits linked to hyperphagia (chronic feeling of hunger)

melatonin

hormone that regulates the sleep-wake cycle

deficits linked to insomnia

oxytocin

produced when having meaningful social interactions (especially in relation to reproduction); “love hormone”

deficits linked to depressive disorders