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Neuroscience, Sixth Edition
Purves • Augustine • Fitzpatrick • Hall • LaMantia • Mooney • Platt • White
Chapter 6: Neurotransmitters and Their Receptors
Multiple Choice
1. What is the main excitatory neurotransmitter in the adult brain?
a. GABA
b. Glutamate
c. Dopamine
d. Serotonin
e. Norepinephrine
Answer: b
Textbook Reference: Overview
Bloom’s Level: 1. Remembering
2. To which category of neurotransmitters does acetylcholine belong? a.
Purines
b. Peptides
c. Amino acids
d. Biogenic amines
e. Small-molecule neurotransmitters
Answer: e
Textbook Reference: Acetylcholine
Bloom’s Level: 1. Remembering
3. What is the mechanism of organophosphate toxicity?
a. Inhibition of acetylcholine reuptake
b. Inhibition of acetylcholinesterase
c. Inhibition of choline reuptake
d. Blockage of postsynaptic channels
e. Interference with the vesicle fusion process
Answer: b
Textbook Reference: Acetylcholine
Bloom’s Level: 2. Understanding
, 4. Which toxin blocks neuromuscular transmission by irreversibly binding to nicotinic
acetylcholine receptors, thus preventing acetylcholine from opening postsynaptic ion
channels?
a. α-bungarotoxin
b. Nicotine
c. Muscarine
d. Atropine
e. Arecoline
Answer: a
Textbook Reference: Acetylcholine
Bloom’s Level: 1. Remembering
5. Which statement about a nicotinic acetylcholine receptor at the neuromuscular junction
is accurate?
a. It has one binding site, and binding of one molecule of acetylcholine to this site
will activate the receptor.
b. It has three binding sites, and binding of only one molecule of acetylcholine to
any of the sites will activate the receptor.
c. It has two binding sites, and binding of two molecules of acetylcholine, one to
each site, is required to activate the receptor.
d. It has two binding sites, and binding of only one molecule of acetylcholine to
either of the sites will activate the receptor.
e. It has four binding sites, and binding of only three molecules of acetylcholine to
any of the sites is required to activate the receptor.
Answer: c
Textbook Reference: Acetylcholine
Bloom’s Level: 2. Understanding
6. Which statement about muscarinic acetylcholine receptors is true?
a. They control a ligand-gated channel.
b. They mediate a rapid response to acetylcholine.
c. They are ionotropic receptors.
d. They are metabotropic receptors.
e. They mediate the effects of acetylcholine at neuromuscular junctions.
Answer: d
Textbook Reference: Acetylcholine
Bloom’s Level: 1. Remembering
7. What is the main cause of myasthenia gravis symptoms?
a. Smaller EEPs and MEEPs
b. Autoimmune reaction against nicotinic acetylcholine receptors
c. Muscle weakness
d. Insufficient quantities of acetylcholine in the synaptic cleft