Neuron MCQs With Answer are essential study aids for B. Pharm students preparing for neuropharmacology and physiology exams. This concise collection focuses on neuronal structure, ion channels, action potentials, synaptic transmission, neurotransmitters, receptor pharmacology and clinical correlations to strengthen conceptual understanding. Each question targets high-yield topics such as resting membrane potential, voltage-gated channels, synaptic plasticity, axonal transport and drug interactions affecting neural signaling. Ideal for revision, practice tests and improving exam accuracy, these MCQs include clear answers and explanations to reinforce learning outcomes and pharmacological implications. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What primarily determines the resting membrane potential of a neuron?
- The concentration of intracellular proteins
- The selective permeability of the membrane to potassium ions
- The number of mitochondria
- The cytosolic pH
Correct Answer: The selective permeability of the membrane to potassium ions
Q2. Which ion channel opens first during the rising phase of an action potential?
- Voltage-gated potassium channel
- Ligand-gated chloride channel
- Voltage-gated sodium channel
- Calcium-activated potassium channel
Correct Answer: Voltage-gated sodium channel
Q3. Which protein actively maintains the sodium and potassium gradients across the neuronal membrane?
- Voltage-gated sodium channel
- Sodium-potassium ATPase
- Na+/Ca2+ exchanger
- Cl− channel
Correct Answer: Sodium-potassium ATPase
Q4. What is the typical value of neuronal resting membrane potential?
- +40 mV
- 0 mV
- −70 mV
- −20 mV
Correct Answer: −70 mV
Q5. Which segment of the neuron is primarily responsible for receiving synaptic inputs?
- Axon hillock
- Dendrites
- Axon terminal
- Myelin sheath
Correct Answer: Dendrites
Q6. Saltatory conduction occurs in neurons because of which feature?
- Continuous distribution of ion channels along the axon
- Myelination and nodes of Ranvier
- High density of synapses on the axon
- Large number of mitochondria
Correct Answer: Myelination and nodes of Ranvier
Q7. Which toxin blocks voltage-gated sodium channels and prevents action potentials?
- Tetrodotoxin (TTX)
- Strychnine
- Bungarotoxin
- Curare
Correct Answer: Tetrodotoxin (TTX)
Q8. Which neurotransmitter is most associated with fast excitatory transmission in the CNS?
- GABA
- Glycine
- Glutamate
- Dopamine
Correct Answer: Glutamate
Q9. Which receptor type is an ionotropic glutamate receptor?
- NMDA receptor
- D1 dopamine receptor
- mGluR5 metabotropic receptor
- GABAB receptor
Correct Answer: NMDA receptor
Q10. Which event most directly triggers neurotransmitter release at the presynaptic terminal?
- Influx of chloride ions
- Depolarization-activated calcium influx
- Activation of metabotropic receptors
- Increase in intracellular cAMP independently
Correct Answer: Depolarization-activated calcium influx
Q11. What is the refractory period during which a neuron cannot fire another action potential regardless of stimulus strength?
- Relative refractory period
- Absolute refractory period
- Synaptic delay
- Afterhyperpolarization
Correct Answer: Absolute refractory period
Q12. Which structure synthesizes and packages neurotransmitters in the presynaptic neuron?
- Mitochondria
- Rough endoplasmic reticulum and Golgi apparatus
- Lysosomes
- Peroxisomes
Correct Answer: Rough endoplasmic reticulum and Golgi apparatus
Q13. Which cellular transport mechanism carries synaptic vesicle precursors from the soma to the axon terminal?
- Retrograde transport via dynein
- Anterograde transport via kinesin
- Passive diffusion
- Endocytosis
Correct Answer: Anterograde transport via kinesin
Q14. Which ion contributes most to the repolarization phase of an action potential?
- Sodium (Na+)
- Calcium (Ca2+)
- Potassium (K+)
- Chloride (Cl−)
Correct Answer: Potassium (K+)
Q15. Which receptor class uses G-proteins and second messengers to modulate neuronal activity?
- Ionotropic receptors
- Transporter proteins
- Metabotropic receptors
- Gap junction channels
Correct Answer: Metabotropic receptors
Q16. Which process decreases synaptic strength and is important for synaptic plasticity?
- Long-term potentiation (LTP)
- Long-term depression (LTD)
- Action potential propagation
- Sodium influx
Correct Answer: Long-term depression (LTD)
Q17. Which glial cell forms myelin in the central nervous system?
- Schwann cell
- Oligodendrocyte
- Astrocyte
- Microglia
Correct Answer: Oligodendrocyte
Q18. Which myelin-forming cell type is found in the peripheral nervous system?
- Satellite cells
- Oligodendrocytes
- Schwann cells
- Ependymal cells
Correct Answer: Schwann cells
Q19. Which of the following increases axonal conduction velocity most effectively?
- Smaller axon diameter
- Increased myelination and larger diameter
- Higher extracellular potassium
- More synapses along the axon
Correct Answer: Increased myelination and larger diameter
Q20. Which synaptic receptor is primarily responsible for inhibitory postsynaptic potentials mediated by chloride influx?
- NMDA receptor
- GABAA receptor
- AMPA receptor
- mAChR
Correct Answer: GABAA receptor
Q21. Which process retrieves synaptic vesicle membrane after neurotransmitter release?
- Exocytosis
- Endocytosis
- Transcytosis
- Autophagy
Correct Answer: Endocytosis
Q22. Which intracellular messenger is commonly involved in modulating synaptic strength via metabotropic receptors?
- Glucose
- cAMP
- Hemoglobin
- Insulin
Correct Answer: cAMP
Q23. Which technique measures ionic currents through individual ion channels in neurons?
- Western blotting
- Patch-clamp recording
- ELISA
- Immunohistochemistry
Correct Answer: Patch-clamp recording
Q24. What effect do local anesthetics like lidocaine have on neurons?
- Activate voltage-gated potassium channels
- Block voltage-gated sodium channels
- Enhance synaptic vesicle fusion
- Open NMDA receptors
Correct Answer: Block voltage-gated sodium channels
Q25. Which event is characteristic of the afterhyperpolarization phase?
- Membrane potential becomes more positive than resting
- Membrane potential transiently becomes more negative than resting
- Sodium channels remain fully open
- Calcium influx ceases permanently
Correct Answer: Membrane potential transiently becomes more negative than resting
Q26. Which neurotransmitter is primarily inhibitory in the adult mammalian CNS?
- Glutamate
- Acetylcholine
- GABA
- Norepinephrine
Correct Answer: GABA
Q27. Which receptor requires both glutamate binding and membrane depolarization to relieve Mg2+ block?
- AMPA receptor
- NMDA receptor
- Kainate receptor
- GABAB receptor
Correct Answer: NMDA receptor
Q28. What is the primary role of synaptic cleft enzymes like acetylcholinesterase?
- Promote neurotransmitter synthesis
- Degrade neurotransmitters to terminate signaling
- Transport neurotransmitters into vesicles
- Open ion channels directly
Correct Answer: Degrade neurotransmitters to terminate signaling
Q29. Which pathology involves autoimmune demyelination in the CNS?
- Myasthenia gravis
- Multiple sclerosis
- Guillain-Barré syndrome
- Parkinson’s disease
Correct Answer: Multiple sclerosis
Q30. Which ion channel is critically involved in neurotransmitter release coupling?
- Voltage-gated sodium channel
- Voltage-gated calcium channel
- Voltage-gated potassium channel
- Ligand-gated chloride channel
Correct Answer: Voltage-gated calcium channel
Q31. Which molecule acts as a retrograde messenger to modulate presynaptic function during plasticity?
- NO (nitric oxide)
- Acetylcholine
- Dopamine
- Insulin
Correct Answer: NO (nitric oxide)
Q32. Which cellular component at the axon hillock integrates inputs to trigger action potentials?
- Synaptic vesicles
- High density of voltage-gated sodium channels
- Myelin internode
- Golgi apparatus
Correct Answer: High density of voltage-gated sodium channels
Q33. Which receptor mediates fast inhibitory transmission in the spinal cord and brainstem via chloride conductance?
- GABAA receptor
- mGluR receptor
- NMDA receptor
- Beta-adrenergic receptor
Correct Answer: GABAA receptor
Q34. Which process describes increased neurotransmitter release probability due to residual presynaptic calcium?
- Synaptic depression
- Paired-pulse facilitation
- Axonal transport
- Receptor desensitization
Correct Answer: Paired-pulse facilitation
Q35. Which ion transporter contributes to setting chloride equilibrium potential in mature neurons?
- NKCC1 (Na+-K+-2Cl− cotransporter)
- KCC2 (K+-Cl− cotransporter)
- Na+/H+ exchanger
- ATP-dependent Cl− pump
Correct Answer: KCC2 (K+-Cl− cotransporter)
Q36. Which mechanism best describes how benzodiazepines enhance GABAergic inhibition?
- Directly open chloride channels without GABA
- Increase affinity of GABA for GABAA receptors
- Block GABA reuptake transporters
- Activate GABAB receptors
Correct Answer: Increase affinity of GABA for GABAA receptors
Q37. Which component of the synapse is primarily postsynaptic and contains neurotransmitter receptors?
- Active zone
- Postsynaptic density
- Synaptic vesicle
- Axon initial segment
Correct Answer: Postsynaptic density
Q38. Which neurotransmitter is synthesized from tyrosine?
- Acetylcholine
- Glutamate
- Dopamine
- GABA
Correct Answer: Dopamine
Q39. Which type of synapse allows direct electrical coupling between neurons?
- Chemical synapse with NMDA receptors
- Electrical synapse via gap junctions
- Axo-axonic chemical synapse
- Neuromuscular junction
Correct Answer: Electrical synapse via gap junctions
Q40. Which pharmacological agent blocks postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction?
- Curare (d-tubocurarine)
- Physostigmine
- Neostigmine
- Sarin
Correct Answer: Curare (d-tubocurarine)
Q41. Which calcium-binding protein mediates fast buffering of intracellular Ca2+ in neurons?
- Sodium-calcium exchanger
- Calmodulin
- Hemoglobin
- Myosin
Correct Answer: Calmodulin
Q42. Which change is most likely after prolonged blockade of postsynaptic receptors?
- Receptor upregulation (increased receptor density)
- Immediate neuronal death
- Permanent loss of synapses
- Decreased neurotransmitter synthesis
Correct Answer: Receptor upregulation (increased receptor density)
Q43. What defines an excitatory postsynaptic potential (EPSP)?
- Hyperpolarization making the membrane more negative
- Depolarization moving membrane potential closer to threshold
- Permanent change in resting potential
- Block of action potential propagation
Correct Answer: Depolarization moving membrane potential closer to threshold
Q44. Which drug increases synaptic acetylcholine by inhibiting acetylcholinesterase?
- Atropine
- Neostigmine
- Propranolol
- Phenytoin
Correct Answer: Neostigmine
Q45. Which neuronal process is essential for development and formation of precise synaptic connections?
- Apoptosis of all neurons
- Axon guidance and growth cone signaling
- Chronic depolarization without guidance cues
- Immediate myelination at birth
Correct Answer: Axon guidance and growth cone signaling
Q46. Which pathology is linked to degeneration of dopaminergic neurons in the substantia nigra?
- Alzheimer’s disease
- Parkinson’s disease
- Multiple sclerosis
- Huntington’s disease
Correct Answer: Parkinson’s disease
Q47. Which molecular change underlies long-term potentiation (LTP) at many glutamatergic synapses?
- Decreased AMPA receptor insertion
- Increased AMPA receptor insertion and trafficking
- Permanent blockade of NMDA receptors
- Removal of postsynaptic densities
Correct Answer: Increased AMPA receptor insertion and trafficking
Q48. Which is a common method neurons use to repolarize after an action potential?
- Opening of voltage-gated calcium channels to influx more positive charge
- Opening of voltage-gated potassium channels to efflux K+
- Importing sodium via transporters
- Generating new synapses
Correct Answer: Opening of voltage-gated potassium channels to efflux K+
Q49. Which factor can increase neuronal excitability by shifting the resting potential closer to threshold?
- Increasing extracellular potassium concentration
- Blocking voltage-gated sodium channels
- Enhancing GABAergic inhibition
- Increasing KCC2 activity to lower intracellular Cl−
Correct Answer: Increasing extracellular potassium concentration
Q50. Which diagnostic marker indicates axonal damage by retrograde transport of toxins or tracers?
- Anterograde tracer accumulation only in terminals
- Retrograde tracing to the cell body
- Increased synaptic cleft width
- Loss of dendritic spines exclusively
Correct Answer: Retrograde tracing to the cell body
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