Neuroscientific Basis and Practical Applications
5th Edition
Author(s)Stephen M. Stahl
TEST BANK
1.
Reference: Ch. 1, The Synapse (Principles of Chemical
Neurotransmission)
Question Stem: A patient receives a drug that selectively blocks
presynaptic voltage-gated calcium channels in cortical neurons.
Which immediate effect at the synapse is most likely?
A. Increased postsynaptic receptor density
B. Reduced synaptic vesicle fusion and neurotransmitter release
C. Enhanced reuptake via presynaptic transporters
D. Increased synthesis of neurotransmitter in the presynaptic
terminal
Correct Answer: B
Rationales:
, • Correct (B): Entry of calcium through presynaptic voltage-
gated calcium channels is the trigger for synaptic vesicle
fusion; blocking these channels reduces neurotransmitter
release. This is a core mechanism described for synaptic
transmission.
• A: Postsynaptic receptor density is regulated over longer
time frames (trafficking/up-/down-regulation), not an
immediate effect of blocking presynaptic calcium entry.
• C: Reuptake transporter activity is separate from calcium-
dependent exocytosis and would not be directly increased
by calcium-channel blockade.
• D: Neurotransmitter synthesis is enzyme-dependent and
slower; acute blockade of calcium channels mainly impairs
release, not immediate synthesis.
Teaching Point: Presynaptic calcium entry is essential for rapid
neurotransmitter release.
Citation: Ch. 1, The synapse (Principles of Chemical
Neurotransmission)
2.
Reference: Ch. 1, Three Dimensions of Neurotransmission —
Space: Volume (Chemical vs Anatomical)
Question Stem: A monoamine released from a brainstem
neuron diffuses widely and modulates many neurons beyond
the immediate synaptic cleft. Stahl would describe this as:
,A. Classical point-to-point synaptic transmission
B. Volume transmission
C. Electrical synaptic transmission
D. Retrograde synaptic inhibition
Correct Answer: B
Rationales:
• Correct (B): Volume transmission describes diffusion of
neurotransmitters through extracellular space to affect
extrasynaptic or distant receptors; this is characteristic of
many monoamines.
• A: Classical synaptic transmission is anatomically
addressed and point-to-point, not the diffuse modulation
described.
• C: Electrical synaptic transmission involves gap junctions
and direct ionic current flow, not extracellular diffusion.
• D: Retrograde signaling is communication from
postsynaptic to presynaptic elements, not diffusion to
many neurons.
Teaching Point: Volume transmission allows neuromodulators
to affect broad brain regions.
Citation: Ch. 1, Three dimensions of neurotransmission —
Space: the chemically addressed nervous system
3.
, Reference: Ch. 1, Time: Fast-onset versus Slow-onset Signals
Question Stem: Which receptor mechanism best explains a
neurotransmitter causing a very rapid (millisecond) excitatory
postsynaptic potential in cortical neurons?
A. G-protein–coupled receptor activating adenylyl cyclase
B. Ionotropic ligand-gated receptor opening a cation channel
C. Activation of intracellular tyrosine kinase receptors
D. Transcriptional activation via second messengers
Correct Answer: B
Rationales:
• Correct (B): Ionotropic ligand-gated receptors (e.g., AMPA
receptors) open ion channels and produce fast millisecond-
scale postsynaptic potentials.
• A: GPCRs (metabotropic) typically mediate slower
responses through second messengers.
• C: Tyrosine kinase receptor signaling is relatively slow and
uncommon for fast synaptic transmission in the CNS.
• D: Transcriptional changes are slow (minutes to hours) and
cannot explain millisecond responses.
Teaching Point: Ionotropic receptors mediate fast synaptic
signaling.
Citation: Ch. 1, Time: fast-onset versus slow-onset signals
4.