Deck 6: Acetylcholine

Question 1

In acetylcholine synthesis,

A) the key catalyzing enzyme is acetylcholinesterase.
B) choline comes from the diet and the liver.
C) acetyl coenzyme A limits synthesis, as it is not found in all cells.
D) coenzyme A is an important precursor.

Answer 1

choline comes from the diet and the liver.

Question 2

Acetylcholine neurons can be identified by the presence of

A) acetylcholinesterase.
B) acetyl coenzyme A.
C) choline acetyltransferase.
D) choline.

Answer 2

choline acetyltransferase.

Question 3

Manipulating acetylcholine synthesis with pharmacological agents

A) is straightforward because of the pharmacological specificity of ChAT inhibitors.
B) has led to significant clinical improvements in disorders like Alzheimer's disease.
C) may yield unfortunate side effects due to peripheral metabolism, such as a fishy odor.
D) is straightforward because it relies entirely on the availability of precursors.

Answer 3

may yield unfortunate side effects due to peripheral metabolism, such as a fishy odor.

Question 4

The function of AChE is to

A) help transmission proceed smoothly at the neuromuscular junction.
B) break acetylcholine into choline and acetic acid.
C) metabolize excess acetylcholine in the terminal button.
D) All of the above

Question 5

Which of the following is not an AChE inhibitor?

A) HC-3
B) Neostigmine
C) Sarin
D) Insecticides

Question 6

The most important difference between pyridostigmine and sarin is that

A) pyridostigmine is an irreversible AChE inhibitor; sarin is not.
B) Sarin does not cross the blood-brain barrier; pyrodostigmine does.
C) Sarin is an irreversible AChE inhibitor; pyrodostigmine is not.
D) pyridostigmine is isolated from Calar beans; sarin is not.

Question 7

Which agent is an irreversible AChE inhibitor?

A) Physostigmine
B) Neostigmine
C) Vesamicol
D) Soman

Question 8

_______ was used during the Gulf War as a protective antidote to nerve gas.

A) Pyridostigmine bromide
B) Sarin
C) Physostigmine bromide
D) Soman

Question 9

Acetylcholine is found in all of the following locations in the PNS except the

A) neuromuscular junction.
B) target organs of the sympathetic nervous system.
C) target organs of the parasympathetic nervous system.
D) sympathetic ganglion.

Question 10

Drugs like Cogentin and Artane would be given to someone with Parkinson's disease because these drugs

A) stimulate dopamine receptors.
B) increase both acetylcholine and dopamine.
C) prevent cell death in late stages of the disorder.
D) decrease acetylcholine receptor activity and help restore a balance with dopamine.

Question 11

LDTg and PPTg cells

A) are cholinergic interneurons.
B) send cholinergic projections to many forebrain structures.
C) utilize dopaminergic signals to control cholinergic cell function.
D) send cholinergic projections to midbrain dopamine cell groups and to thalamic areas.

Question 12

Why have researchers been particularly interested in the agent 192 IgG-saporin?

A) It is a new antidote for nerve gas exposure.
B) It is a neurotoxin for cells in the brain stem cholinergic system.
C) It destroys BFCS cells and causes cognitive deficits.
D) It is a drug that might have use in the treatment of Alzheimer's disease.

Question 13

Nicotinic receptors

A) are found on muscle cells at the neuromuscular junction.
B) are metabotropic receptors.
C) can be overly stimulated by the poison d-tubocurarine.
D) possess two protein subunits, one $\alpha$ unit and one $\beta$ unit.

Question 14

Which statement does not accurately describe activity at the nicotinic receptor?

A) The channel opens rapidly and depolarization occurs.
B) Sodium and/or calcium ions enter the next cell.
C) Prolonged stimulation of receptors can lead to desensitization.
D) Nicotinic receptors are only found on cell bodies and dendrites in the brain, not on nerve terminals.

Question 15

Activation of nicotinic receptors can increase release of neurotransmitter without affecting the firing rate of a neuron

A) by allowing neurotransmitter to pass through the channel of the receptor.
B) if the nicotinic receptors are located right on the presynaptic terminal of the neuron.
C) only if the neuron in question has nicotinic receptors localized to its dendrites.
D) only at the neuromuscular junction.

Question 16

Unlike _______, _______ can readily cross the blood-brain barrier and thus have effects on the central nervous system.

A) d-tubocurarine; mecamylamine
B) atropine; succinylcholine
C) mecamylamine; d-tubocurarine
D) atropine; D-tubocurarine

Question 17

Muscarinic receptors in the brain play a role in all of the following except

A) motor function.
B) cognition.
C) tobacco smoking.
D) dependence and addiction.

Question 18

An antagonist that selectively blocks M₅ cholinergic receptors in the midbrain could potentially be used to treat

A) diabetes.
B) dry-mouth effect.
C) drug dependence.
D) heart disease.

Question 19

Stimulation of _______ muscarinic receptors can decrease heart rate, while activation of peripheral M₃ receptors can lead to an increase in _______.

A) M₅; heart rate
B) M₃; pupillary dilation
C) M₅; dry-mouth
D) M₂; insulin release

Question 20

Parasympatholytic agents

A) have medical uses in ophthalmology and surgery.
B) include atropine, which constricts the pupils.
C) are rarely toxic, which is why they have been used throughout history.
D) include pilocarpine and arecoline.

Question 21

Explain how a reversible AChE antagonist like pyridostigmine bromide can be used as an antidote of sorts against an irreversible AChE antagonist nerve gas such as sarin.

Question 22

Write an informative and coherent paragraph incorporating the following terms: myasthenia gravis, nicotinic receptor, neuromuscular junction, autoimmune disorder, neostigmine.

Question 23

Describe the distribution of acetylcholine neurons outside the central nervous system (i.e., in the periphery) and indicate which cholinergic receptors would be present postsynaptically in the various locations.

Question 24

Identify the cholinergic circuits in the central nervous system that are most important in cognitive functioning. Give one piece of evidence for your answer.

Question 25

Explain how 192 IgG-saporin works to create selective cholinergic lesions in the brain. Describe evidence suggesting that cortical ACh is important for attentional processing.

Question 26

Describe, in detail, the evidence supporting the assertion that muscarinic receptors may play a role in drug dependence and reward.