Getting your questions ready
Getting your questions ready
Beat the crowd
10 questions No timer
50 free Neuroscience trivia questions with answers — science & nature quiz, new questions added Aug 2026.
42 free Neuroscience trivia questions with answers. Neuroscience trivia tends to stop at 'the brain has 86 billion neurons'. This quiz goes further, into how those neurons actually work and how we found out: the squid axon that gave Hodgkin and Huxley their model, the dream that told Otto Loewi how nerves talk to each other, the staining method Golgi discovered and Cajal used against him, the railway foreman with a rod through his skull, and the patient known as H.M. who could not make new memories. It covers anatomy (cerebellum, hippocampus, amygdala, corpus callosum, Broca's area), chemistry (dopamine, serotonin, acetylcholine, botulinum toxin, tetrodotoxin), methods (EEG, optogenetics, the C. elegans connectome) and the oddities of the mind, from face blindness to split-brain patients arguing with their own hands. Roughly a third of the questions are easy enough for a curious teenager; the rest climb toward the Nobel Prize citations. Every answer was checked against Wikipedia's articles on the relevant structure, molecule or scientist, and each question carries its source.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Roughly how many neurons does the adult human brain contain?
86 billion
There are about as many non-neuronal glial cells again, and the whole organ is only about 2% of body weight.
Q 02The brain uses roughly what share of the body's energy?
Up to 20%
More than any other organ, for something that weighs a little over a kilogram.
Q 03The electrical signals neurons fire are called what?
Action potentials
A neuron's sequence of them is called its spike train; some plant and pancreatic cells fire them too.
Q 04Which animals are the only ones with no neurons at all?
Sponges and placozoans
The ability to fire electrical signals seems to have appeared 700 to 800 million years ago; plants and fungi never evolved it.
Q 05The junction across which one neuron signals to another cell is called what?
A synapse
They come in chemical and electrical varieties; the electrical kind couples cells through gap junctions.
Q 06The fatty sheath that insulates axons and speeds up conduction is called what?
Myelin
The gaps between segments, the nodes of Ranvier, let the impulse jump from node to node in what is called saltatory conduction.
Q 07Which glial cells wrap axons in their insulating sheath inside the brain and spinal cord?
Oligodendrocytes
In the peripheral nerves the same job is done by Schwann cells; glia make up over half the volume of neural tissue.
Q 08The cerebellum takes up only about 10% of the skull's contents by volume yet holds what?
More neurons than everything else combined
The credit goes to its vast numbers of tiny granule cells; its name is Latin for 'little brain'.
Q 09The memory-forming structure deep in the temporal lobe is named after its resemblance to which animal?
A seahorse
The Venetian anatomist Aranzi first compared it to a silkworm in 1587 before settling on the seahorse.
Q 10Which limbic structure, named from the Greek for 'almond', is central to processing fear?
The amygdala
It was first identified and named by Karl Friedrich Burdach in 1822.
Q 11The thick fibre bundle that links the two cerebral hemispheres is found only in which group of animals?
Placental mammals
It is the brain's largest white-matter structure, about 10 cm long with 200 to 300 million axons.
Q 12Broca's area, linked to speech production, sits in which lobe?
Frontal
Paul Broca identified it from two patients who had lost the ability to speak after injury there.
Q 13Which lobe of the cerebrum is dedicated to vision?
Occipital
The one at the front of the head handles executive functions such as planning and self-control.
Q 21Modern pharmacology says dopamine signals not pleasure itself but what?
Motivational salience
It flags how desirable or aversive an outcome is, pushing behaviour toward or away from it; it is made from L-DOPA in the brain and kidneys.
Q 22About 90% of the body's serotonin is made where?
In the gut
Enterochromaffin cells in the gastrointestinal tract use it to regulate intestinal movement; only 1-2% is in the central nervous system.
Q 23Botulinum toxin causes flaccid paralysis by blocking neurotransmitter release where?
At the neuromuscular junction
Q 14Phineas Gage survived an 1848 accident in which what passed through his head?
A tamping iron
He was setting a blasting charge near Cavendish, Vermont; the case became known as the American Crowbar Case.
Q 15Patient H.M. lost the ability to form new memories after 1953 surgery removed most of which brain structure?
The hippocampus
Henry Molaison's operation was meant to cure his epilepsy; he became the most studied patient in memory research.
Q 16Which two rivals shared the 1906 Nobel Prize for work on the structure of the nervous system?
Golgi and Ramón y Cajal
The Italian's silver 'black reaction' stain let the Spaniard draw the neurons that disproved the Italian's own theory of a continuous network.
Q 17Santiago Ramón y Cajal was the first person from which country to win a scientific Nobel Prize?
Spain
Hundreds of his drawings of branching brain cells are still used for teaching.
Q 18Hodgkin and Huxley worked out how nerve impulses propagate using which animal's giant axon?
The squid
Their 1952 equations won the 1963 Nobel Prize and are still the standard conductance-based model of the neuron.
Q 19Otto Loewi's Nobel-winning proof that nerves signal chemically came to him how?
In a dream, twice
He woke on Easter Saturday 1921 unable to remember it, then dreamed it again the next night and went straight to the lab to stimulate a frog's heart.
Q 20Which neurotransmitter do motor neurons release to make muscles contract?
Acetylcholine
It is also the main transmitter of the parasympathetic nervous system, which is why drugs that block it can cause paralysis.
In heavily diluted form the same mechanism smooths wrinkles and treats migraine as Botox.
Q 24Tetrodotoxin takes its name from the order of fish that includes which species?
Pufferfish
Blue-ringed octopuses and rough-skinned newts carry it too, and it is actually made by symbiotic bacteria.
Q 25The blood-brain barrier is formed mainly by which type of cell lining the brain's capillaries?
Endothelial
Astrocyte end-feet and pericytes complete the seal, which lets oxygen and hormones through but blocks most pathogens and antibodies.
Q 26Roughly how much cerebrospinal fluid does the human body produce each day?
About 500 mL
Only about 125 mL is present at any one time; the rest is continually absorbed, cushioning the brain in the meantime.
Q 27The glymphatic system, which flushes waste from the brain, works hardest during what?
Slow-wave sleep
The extracellular space expands during deep sleep, which may be part of why sleep feels restorative.
Q 28Mirror neurons were first recorded in the premotor cortex of which animal, by Rizzolatti's team in Parma?
The macaque monkey
They fire both when the animal acts and when it watches another do the same thing; their function in humans is still debated.
Q 29Which husband-and-wife team discovered grid cells in the brain in 2005?
Edvard and May-Britt Moser
They shared the 2014 Nobel Prize with John O'Keefe, who had found hippocampal place cells decades earlier.
Q 30Place cells fire when an animal is in a particular spot; collectively they are thought to form what?
A cognitive map
They are pyramidal neurons in the memory-forming region of the temporal lobe, and they can suddenly 'remap' when the environment changes.