Dopamine Trivia
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59 free Dopamine trivia questions with answers — science & nature quiz, new questions added Sep 2026.
Dopamine is the most talked-about molecule in the brain and the most misunderstood, and this trivia quiz sets the record straight. It covers the chemistry (which amino acid it comes from, which enzymes make and destroy it, why it cannot cross the blood-brain barrier), the anatomy (the substantia nigra, the ventral tegmental area, the mesolimbic pathway and the surprisingly small number of neurons involved) and the science of reward, from Olds and Milner's lever-pressing rats to Wolfram Schultz's reward prediction error and the difference between wanting and liking. It also covers the medicine and the history: Parkinson's disease and L-DOPA, the dopamine hypothesis of schizophrenia, how cocaine and Ritalin work, why dopamine stops nausea and milk production, the 1910 synthesis in London, Kathleen Montagu's 1957 discovery of dopamine in the human brain and Arvid Carlsson's Nobel Prize. There are lighter questions too: which fruit is richest in dopamine, what an octopus's ink contains and what "dopamine fasting" actually means. Every answer was verified against Wikipedia's articles on dopamine, the reward system and related topics, and each question links to its source. Try our Human Brain and Nicotine quizzes next.
30 of 59 questions with answers and explanations. Play the quiz
Q 01The enzyme that turns L-DOPA into dopamine also makes which other famous mood chemical?
Serotonin
Serotonin comes off the same production line: one enzyme clips a carboxyl group from L-DOPA to give dopamine and from 5-HTP to give serotonin. Children born without it run short of both.
Q 02Rather than pleasure itself, mainstream pharmacology holds that dopamine signals what?
Motivational salience
Motivational salience is how strongly an outcome grabs you, good or bad. One group of dopamine neurons fires for unpleasant events as well as for treats.
Q 03Dopamine belongs to which chemical family, along with the stress hormones epinephrine and norepinephrine?
Catecholamines
Catecholamines are built in sequence: the body turns dopamine into norepinephrine and then into epinephrine, so the so-called reward chemical is also the raw material for fight or flight.
Q 04Dopamine synthesis starts with which essential amino acid, named in the warning on diet-soda cans?
Phenylalanine
Phenylalanine is a building block of the sweetener aspartame. The label protects people with the inherited disorder PKU, who cannot break it down, which is why newborns are routinely screened for it.
Q 05Which enzyme carries out the rate-limiting step of dopamine synthesis, turning an amino acid into L-DOPA?
Tyrosine hydroxylase
Tyrosine hydroxylase sets the pace for the whole pathway. When dopamine builds up it latches onto the enzyme and slows it down, a built-in brake against overproduction.
Q 06Turning dopamine into norepinephrine needs which vitamin, also used to build collagen?
Vitamin C
Vitamin C is used up in the reaction: each time the copper-containing enzyme adds an oxygen to dopamine, a molecule of the vitamin gives up electrons to make it happen.
Q 07What is the main inactive end product of dopamine breakdown, excreted in urine?
Homovanillic acid
Homovanillic acid leaves the body in urine, which makes it a handy clue for doctors: a raised level helps reveal neuroblastoma, a childhood tumour that churns out dopamine-family chemicals.
Q 08Which two enzymes, along with aldehyde dehydrogenase, break dopamine down?
Monoamine oxidase and COMT
Monoamine oxidase and COMT are both drug targets: Parkinson's medicines that block either enzyme slow the breakdown of dopamine, so each dose of treatment lasts longer.
Q 09Which Back to the Future star was diagnosed with Parkinson's, a disease of dying dopamine cells?
Michael J. Fox
Michael J. Fox noticed a twitching little finger while filming Doc Hollywood. He kept the diagnosis private until 1998, then launched the research foundation that bears his name.
Q 10Dopamine blockers such as haloperidol are used to calm the involuntary movements of which condition?
Tourette syndrome
Tourette syndrome tics respond most reliably to dopamine blockers, yet many people with the condition never need medication, and the tics usually ease by the early twenties.
Q 11Anthropologist Helen Fisher found dopamine-rich reward areas lit up when her brain-scan volunteers gazed at photos of whom?
Their new sweetheart
Their new sweetheart lit up the same dopamine circuitry that drives cravings. Fisher went on to argue that early romantic love is a natural addiction, complete with tolerance, withdrawal and relapse.
Q 12Tetrabenazine, which blocks dopamine storage, calms which disease's jerky movements?
Huntington's
Huntington's disease causes chorea, sudden movements a person cannot control. The drug blocks VMAT2, the transporter that loads dopamine into vesicles, so less is released and the movements settle.
Q 13A McGill University study found the brain releases dopamine at the moment a favourite piece of music produces what?
Q 21Robinson and Berridge's addiction theory split reward into which two parts, only one driven by dopamine?
Wanting and liking
Wanting and liking turned out to be separate systems: dopamine fuels the craving, not the pleasure. That is why people with addictions can want a drug more and more while enjoying it less.
Q 22Cambridge neuroscientist Wolfram Schultz discovered that dopamine neurons signal what?
Errors in reward prediction
Errors in reward prediction drive the cells: a better-than-expected reward makes them fire, a fully expected one draws no response, and a reward that fails to arrive makes their firing dip.
Q 23Why is L-DOPA given to Parkinson's patients instead of dopamine itself?
Chills
Chills marked the peak, but the scans held a second surprise: a different dopamine region fired during the build-up, while listeners were still only anticipating their favourite passage.
Q 14The substantia nigra, whose dopamine neurons die in Parkinson's, sits in which part of the brain?
The midbrain
The midbrain houses this structure, whose Latin name means black substance. By the time Parkinson's symptoms appear, a large share of its dopamine cells have already died.
Q 15What gives the substantia nigra its dark colour?
Neuromelanin
Neuromelanin is a dark pigment that builds up in dopamine cells as we age. In Parkinson's those pigmented cells die off, and the pigment is lost with them.
Q 16Brain scans showed Parkinson's patients releasing a substantial burst of their own dopamine after being given what?
A placebo
A placebo was enough: simply expecting relief made the patients' damaged dopamine system release a substantial burst, showing the placebo effect is real brain chemistry rather than imagination.
Q 17Which 'reward' projection carries dopamine from the ventral tegmental area to the nucleus accumbens?
The mesolimbic pathway
The mesolimbic pathway sits at the heart of addiction research: cocaine, alcohol and nicotine can all leave its dopamine system over-responsive long after the drug has worn off.
Q 18Dopamine from the hypothalamus is the main inhibitor of which pituitary hormone?
Prolactin
Prolactin is the milk-making hormone, held in check by a steady supply of dopamine. That is why dopamine-blocking drugs can trigger breast-milk production, even in men.
Q 19Bright daylight makes the retina release dopamine, a leading explanation for why outdoor play protects children against what?
Short-sightedness
Short-sightedness develops when the eyeball grows too long, and dopamine released by the retina in bright light appears to act as a stop signal for that growth.
Q 20In Olds and Milner's famous experiment, rats kept pressing a lever again and again to get what?
A jolt to the brain
A jolt to the brain, delivered through an implanted electrode, beat every natural reward: the rats pressed on and on, forgetting to eat and drink.
It cannot cross the blood-brain barrier
It cannot cross the blood-brain barrier, whereas L-DOPA slips through and is turned into dopamine inside the brain. A partner drug, carbidopa, stops the body converting it too early, so a smaller dose does the job.
Q 24L-DOPA was first isolated in 1913 from the seeds of which plant?
The broad bean
The broad bean, or fava bean, holds enough L-DOPA to act like the drug: in a small trial, Parkinson's patients who ate a large plate of cooked beans moved markedly better for the next few hours.
Q 25Which Vienna-based scientist found that Parkinson's disease stems from a dopamine deficiency?
Oleh Hornykiewicz
Oleh Hornykiewicz found dopamine badly depleted in the brains of Parkinson's patients who had died. A year later he and a Vienna neurologist injected L-DOPA, and bedridden patients stood up and walked.
Q 26Oliver Sacks's memoir Awakenings, filmed in 1990, describes giving L-DOPA to survivors of which epidemic?
Encephalitis lethargica
Encephalitis lethargica swept the world in the 1910s and 1920s, leaving survivors frozen in hospital wards for decades. In 1969 L-DOPA had some of them up and dancing, though for many the benefits proved erratic or short-lived.
Q 27Which misfolded protein clumps into Lewy bodies in Parkinson's disease?
Alpha-synuclein
Alpha-synuclein clumps turned up throughout Robin Williams's brain at autopsy. The actor had been told he had Parkinson's a few months before he died; the Lewy bodies pointed to a related dementia.
Q 28Dopamine-mimicking Parkinson's drugs such as pramipexole carry a warning about which unexpected side effect?
Compulsive gambling
Compulsive gambling, along with sudden urges to shop, overeat or have sex, has been reported in patients with no history of it. The drugs switch on the brain's reward circuits as well as its movement circuits.
Q 29Cocaine raises dopamine levels in the synapse mainly by doing what?
Blocking the dopamine transporter
Blocking the dopamine transporter jams the pump that recycles dopamine, so it piles up between nerve cells. With repeated use the brain adapts, and everyday rewards such as food start to register less.
Q 30The founding president of which company admitted in 2017 that it was built to give users 'a little dopamine hit'?
Facebook's Sean Parker, who earlier co-founded Napster, called its likes a social-validation feedback loop that exploits a weakness in human psychology. God only knows, he added, what it is doing to children's brains.