Stahl's Essential Psychopharmacology
Neuroscientific Basis and Practical Applications
5th Edition
Author(s)Stephen M. Stahl
TEST BANK
Item 1
Reference: Ch. 1, Chemical Neurotransmission (Principles of
Chemical Neurotransmission).
Question Stem: A 32-year-old patient is started on a medication
thought to reduce synaptic neurotransmitter release by
inhibiting presynaptic calcium entry. Which presynaptic process
is most directly interrupted by decreased intracellular Ca²⁺?
A. Vesicle docking to the presynaptic membrane
B. Fusion of synaptic vesicles with the membrane (exocytosis)
C. Reuptake of neurotransmitter via transporters
D. Enzymatic breakdown of neurotransmitter in the synaptic
cleft
Correct Answer: B
Rationales:
, • B (Correct): Calcium influx through voltage-gated calcium
channels is the immediate trigger for SNARE-mediated
vesicle fusion and exocytotic release of neurotransmitter;
lowering intracellular Ca²⁺ prevents this fusion. (Textbook
mechanism linking Ca²⁺ entry to vesicle fusion).
• A: Docking occurs before the Ca²⁺-triggered fusion step;
docking may remain intact even if Ca²⁺ entry is reduced.
• C: Reuptake is mediated by membrane transporters and is
downstream of release; it is not directly triggered by
presynaptic Ca²⁺ influx.
• D: Enzymatic breakdown in the cleft (e.g.,
acetylcholinesterase) occurs extracellularly and is
independent of presynaptic Ca²⁺ entry.
Teaching Point: Presynaptic Ca²⁺ influx triggers vesicle fusion
and neurotransmitter exocytosis.
Citation: Ch. 1, Chemical Neurotransmission (pp. 1–28).
Cambridge Core
Item 2
Reference: Ch. 1, Chemical Neurotransmission (Synaptic
Structure & Release).
Question Stem: A psychiatric patient receives botulinum toxin
for a comorbid condition. Which presynaptic molecular target
,best explains the drug’s ability to reduce peripheral
neurotransmitter release?
A. Voltage-gated calcium channels
B. Synaptic vesicle SNARE proteins (e.g., SNAP-25)
C. Postsynaptic ligand-gated ion channels
D. Monoamine oxidase in the cytoplasm
Correct Answer: B
Rationales:
• B (Correct): Botulinum toxin cleaves SNARE proteins (such
as SNAP-25), preventing vesicle fusion and
neurotransmitter release; this is a classic presynaptic
mechanism.
• A: Botulinum toxin does not primarily block calcium
channels; that would be another mechanism to reduce
release but is not botulinum’s action.
• C: Postsynaptic ligand-gated channels are downstream
receptors and are not cleaved or inhibited by botulinum
toxin.
• D: Monoamine oxidase is an intracellular degradative
enzyme and not the target of botulinum toxin’s inhibition
of exocytosis.
Teaching Point: Botulinum toxins block exocytosis by cleaving
SNARE proteins.
, Citation: Ch. 1, Chemical Neurotransmission (pp. 1–28).
Cambridge Core
Item 3
Reference: Ch. 1, Chemical Neurotransmission
(Neurotransmitter Pools & Vesicles).
Question Stem: While reviewing mechanisms of synaptic
release, a student asks which vesicle pool is immediately
available for release during a single action potential. What is the
best answer?
A. Reserve pool
B. Readily releasable pool (docked vesicles)
C. Endosomal pool
D. Lysosomal pool
Correct Answer: B
Rationales:
• B (Correct): The readily releasable pool consists of docked
vesicles positioned for rapid fusion on Ca²⁺ entry and is the
source for immediate neurotransmitter release.
• A: The reserve pool supplies vesicles during sustained
activity but is not the immediate source for a single action
potential.
• C: Endosomal structures are part of vesicle recycling, not
the immediate releasable pool for fast transmission.
Neuroscientific Basis and Practical Applications
5th Edition
Author(s)Stephen M. Stahl
TEST BANK
Item 1
Reference: Ch. 1, Chemical Neurotransmission (Principles of
Chemical Neurotransmission).
Question Stem: A 32-year-old patient is started on a medication
thought to reduce synaptic neurotransmitter release by
inhibiting presynaptic calcium entry. Which presynaptic process
is most directly interrupted by decreased intracellular Ca²⁺?
A. Vesicle docking to the presynaptic membrane
B. Fusion of synaptic vesicles with the membrane (exocytosis)
C. Reuptake of neurotransmitter via transporters
D. Enzymatic breakdown of neurotransmitter in the synaptic
cleft
Correct Answer: B
Rationales:
, • B (Correct): Calcium influx through voltage-gated calcium
channels is the immediate trigger for SNARE-mediated
vesicle fusion and exocytotic release of neurotransmitter;
lowering intracellular Ca²⁺ prevents this fusion. (Textbook
mechanism linking Ca²⁺ entry to vesicle fusion).
• A: Docking occurs before the Ca²⁺-triggered fusion step;
docking may remain intact even if Ca²⁺ entry is reduced.
• C: Reuptake is mediated by membrane transporters and is
downstream of release; it is not directly triggered by
presynaptic Ca²⁺ influx.
• D: Enzymatic breakdown in the cleft (e.g.,
acetylcholinesterase) occurs extracellularly and is
independent of presynaptic Ca²⁺ entry.
Teaching Point: Presynaptic Ca²⁺ influx triggers vesicle fusion
and neurotransmitter exocytosis.
Citation: Ch. 1, Chemical Neurotransmission (pp. 1–28).
Cambridge Core
Item 2
Reference: Ch. 1, Chemical Neurotransmission (Synaptic
Structure & Release).
Question Stem: A psychiatric patient receives botulinum toxin
for a comorbid condition. Which presynaptic molecular target
,best explains the drug’s ability to reduce peripheral
neurotransmitter release?
A. Voltage-gated calcium channels
B. Synaptic vesicle SNARE proteins (e.g., SNAP-25)
C. Postsynaptic ligand-gated ion channels
D. Monoamine oxidase in the cytoplasm
Correct Answer: B
Rationales:
• B (Correct): Botulinum toxin cleaves SNARE proteins (such
as SNAP-25), preventing vesicle fusion and
neurotransmitter release; this is a classic presynaptic
mechanism.
• A: Botulinum toxin does not primarily block calcium
channels; that would be another mechanism to reduce
release but is not botulinum’s action.
• C: Postsynaptic ligand-gated channels are downstream
receptors and are not cleaved or inhibited by botulinum
toxin.
• D: Monoamine oxidase is an intracellular degradative
enzyme and not the target of botulinum toxin’s inhibition
of exocytosis.
Teaching Point: Botulinum toxins block exocytosis by cleaving
SNARE proteins.
, Citation: Ch. 1, Chemical Neurotransmission (pp. 1–28).
Cambridge Core
Item 3
Reference: Ch. 1, Chemical Neurotransmission
(Neurotransmitter Pools & Vesicles).
Question Stem: While reviewing mechanisms of synaptic
release, a student asks which vesicle pool is immediately
available for release during a single action potential. What is the
best answer?
A. Reserve pool
B. Readily releasable pool (docked vesicles)
C. Endosomal pool
D. Lysosomal pool
Correct Answer: B
Rationales:
• B (Correct): The readily releasable pool consists of docked
vesicles positioned for rapid fusion on Ca²⁺ entry and is the
source for immediate neurotransmitter release.
• A: The reserve pool supplies vesicles during sustained
activity but is not the immediate source for a single action
potential.
• C: Endosomal structures are part of vesicle recycling, not
the immediate releasable pool for fast transmission.
