Neurotransmitters
0Loading crowd target
0Loading crowd target
7correct to beat the crowd
40 free Neurotransmitters trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Every thought, movement and mood depends on tiny amounts of signalling molecules passing between nerve cells. Dopamine, serotonin, acetylcholine and GABA have become household names, yet few people could say what each one really does, or how a medicine or a poison changes the conversation. This quiz covers the ground students are tested on: how a neuron stores and releases its transmitters, what happens at the synapse, and which transmitter is tied to movement, sleep, pain or memory. It also covers the drugs, toxins and disorders that work by boosting or blocking those signals, and the researchers whose experiments revealed them. It suits psychology, biology and nursing students revising for a test, and anyone curious about how the brain works. Every answer comes with a short explanation, so you can play it straight through or print it for a study group.
30 of 40 questions with answers and explanations. Play the quiz
Q 01Neurotransmitters are released by one neuron and picked up by receptors on the next: what exactly are they?
Chemical messengers
Chemical messengers are how neurons signal across the tiny gap between them. Scientists know of at least 100 neurotransmitters and suspect many others are yet to be discovered.
Q 02Death of dopamine-producing neurons in the brain's substantia nigra causes which movement disorder?
Parkinson's disease
Parkinson's disease is spotted late in the damage: by the time movement symptoms appear, 50–80% of the dopamine neurons in the substantia nigra have already degenerated.
Q 03Wrinkle-smoothing injections block acetylcholine release using a diluted form of the toxin behind which illness?
Botulism
Botulism is the paralysing illness caused by botulinum toxin, the active ingredient of Botox. By stopping nerve endings releasing acetylcholine, it relaxes the muscles under facial wrinkles.
Q 04Serotonin is famous as a mood transmitter, but about 90% of the body's supply is made where?
The gut
The gut makes most of it: enterochromaffin cells in the gastrointestinal tract produce serotonin, which regulates intestinal movements.
Q 05Caffeine keeps people alert by blocking the brain's receptors for which sleepiness-promoting molecule?
Adenosine
Adenosine builds up in the brain during waking hours, creating the need to sleep. Caffeine has a similar three-dimensional structure, so it binds to the same receptors and blocks them.
Q 06Which hormone triggers contractions during labour and also acts in the brain to strengthen social bonding?
Oxytocin
Oxytocin is made in the hypothalamus and released by the posterior pituitary. Its role in bonding has earned it the nicknames 'cuddle hormone' and 'love hormone'.
Q 07Which amino acid, wrongly blamed for drowsiness after a turkey dinner, is the body's raw material for serotonin?
Tryptophan
Tryptophan is no more plentiful in turkey than in other meats. The after-dinner slump may come instead from the other foods on the plate, particularly carbohydrates.
Q 08What does the brain release during hard exercise that blocks pain like the body's own morphine?
Endorphins
Endorphins take their name from a contraction of 'endogenous morphine', meaning morphine made within the body. They block the perception of pain and increase feelings of well-being.
Q 09Fluoxetine, which treats depression by blocking the reuptake of serotonin, became famous under which brand name?
Prozac
Prozac was the name Eli Lilly gave the drug, which it began marketing in the US a month after approval in December 1987. Annual US sales reached $350 million within a year.
Q 10Which mind-altering drug, first made by Swiss chemist Albert Hofmann, works mainly through serotonin receptors?
LSD
LSD is a semisynthetic drug derived from ergot. Hofmann first made it in 1938 but discovered its potent psychedelic effects only in 1943, after accidentally ingesting some.
Q 11Which drug is best known for jamming the transporter that clears dopamine from the synapse?
Cocaine
Cocaine binds tightly to the dopamine transporter and blocks its function, so dopamine lingers in the synapse. The drug comes from the leaves of two coca species native to South America.
Q 12Valium and Xanax calm anxiety by enhancing the effect of GABA: to which drug class do they belong?
Benzodiazepines
Benzodiazepines began with an accident: Leo Sternbach discovered the first, Librium, by chance in 1955. Valium followed in 1963.
Q 13Methylphenidate, a stimulant that blocks dopamine reuptake, is prescribed for ADHD under which brand name?
Ritalin
Q 21Neurotransmitters wait at the axon terminal packed inside which tiny sacs, the subject of a 2013 Nobel Prize?
Vesicles
Vesicles empty their cargo by fusing with the nerve cell's membrane. Thomas Südhof, James Rothman and Randy Schekman won the 2013 Nobel Prize for their work on how they are trafficked.
Q 22When a nerve impulse reaches the axon terminal, an inrush of which ion triggers the release of neurotransmitter?
Calcium
Calcium ions flow in through voltage-dependent channels and bind to synaptotagmin proteins, which lets the stored packets of transmitter fuse with the membrane and spill into the synapse.
Q 23Which brief electrical signal travels down a neuron's axon and triggers neurotransmitter release at the far end?
Action potential
Ritalin was the original Novartis brand for the drug. Because the extra dopamine acts on the brain's reward system, the drug can also induce euphoria.
Q 14Haloperidol and chlorpromazine, drugs that block dopamine D2 receptors, are used mainly to treat which condition?
Schizophrenia
Schizophrenia is the principal use of antipsychotics, a drug class first introduced in the 1950s. Most of them work in much the same way: by blocking D2 dopamine receptors.
Q 15Loss of the brain cells that release orexin, a wakefulness-promoting peptide, causes which sleep disorder?
Narcolepsy
Narcolepsy type 1 follows the loss of the orexin-releasing neurons in the lateral hypothalamus. It can bring cataplexy: a sudden loss of muscle tone triggered by strong emotion.
Q 16Donepezil, sold as Aricept, slows the breakdown of acetylcholine to ease the symptoms of which condition?
Alzheimer's disease
Alzheimer's disease is treated with donepezil because the drug blocks acetylcholinesterase, the enzyme that breaks acetylcholine down. There is no evidence that it alters the course of the illness.
Q 17Which drug, carried as the nasal spray Narcan, reverses overdoses by blocking the brain's opioid receptors?
Naloxone
Naloxone given as a nasal spray takes effect in about ten minutes and is commonly used to restore breathing after an opioid overdose. Its block lasts only 30 to 90 minutes.
Q 18Which branched extensions of a neuron, studded with receptors, receive signals from other nerve cells?
Dendrites
Dendrites take their name from the Greek word for 'tree'. Those of a single large pyramidal cell receive signals from about 30,000 other neurons.
Q 19Unlike neurotransmitters crossing a synapse, hormones reach distant organs by which route?
The bloodstream
The bloodstream carries hormones from the glands that secrete them to distant organs and tissues. A neurotransmitter, by contrast, often acts over distances measured in micrometres.
Q 20Which drug 'awakened' survivors of the 1920s encephalitis lethargica epidemic in Oliver Sacks's book Awakenings?
L-DOPA
L-DOPA is the precursor the body turns into dopamine. Sacks found its effects on his patients' symptoms generally dramatic but temporary.
An action potential is an all-or-none signal: it either occurs fully or does not occur at all. The sodium-based kind is over in about a millisecond.
Q 24GABA, the transmitter whose work is enhanced by Valium, has which kind of effect on most mature neurons?
Inhibitory
Inhibitory transmitters reduce a neuron's excitability. GABA, the principal one in the mature brain, works through receptors whose channels carry chloride ions across the cell membrane.
Q 25Morphine switches on opioid receptors rather than blocking them: what is a drug that acts this way called?
Agonist
An agonist binds to a receptor and activates it, much as the body's own transmitter would. An antagonist does the reverse and blocks the receptor instead.
Q 26Which amino acid, the nervous system's most abundant excitatory transmitter, is also the raw material for GABA?
Glutamate
Glutamate is the transmitter of nearly all the excitatory neurons in the central nervous system. A single enzyme, glutamate decarboxylase, converts it into GABA.
Q 27The locus coeruleus, a 'blue spot' in the brainstem, is the brain's principal source of which alertness transmitter?
Norepinephrine
Norepinephrine release is lowest during sleep, rises during wakefulness and reaches much higher levels in situations of stress or danger: the fight-or-flight response.
Q 28Older allergy tablets cause drowsiness by blocking brain receptors for which wake-promoting transmitter?
Histamine
Histamine neurons in the hypothalamus fire rapidly during wakefulness and stop firing altogether during sleep. Newer allergy drugs cross into the brain far less, so they sedate less.
Q 29Which gas, whose signalling role in the body won a 1998 Nobel Prize, also works as a neurotransmitter?
Nitric oxide
Nitric oxide is highly reactive, with a lifetime of a few seconds, yet it diffuses freely across cell membranes, so it has no need of a receptor on the cell surface.
Q 30Which pharmacologist proved that nerves release a transmitter by passing fluid between two frog hearts?
Otto Loewi
Otto Loewi said the experiment came to him in a dream. He named the heart-slowing substance 'Vagusstoff', and it was later found to be acetylcholine.