Chapter 49. Principles of Neuropharmacology and Therapeutics Flashcards
Question 49-1:
Which of the following statements regarding GABA and its receptors are true?
1. GABA is mainly inhibitory
2. Benzodiazepines bind to GABA receptors
3. Barbiturates bind to GABA receptors
4. Baclofen binds to GABA receptors
Select: A = 1.2. 3. B = I. 3. C = 2, 4. D = 4 only. E = All
Answer 49-1: E.
All oftbese are true, although these are not
unique functions of the chemicals. Actions
from binding to me GABA receptors may be
only part of the pharmacologic action of some
of these medications. (p879-881)
Question 49-2:
Which of the following statements are true regarding glutamate and aspartate?
1.Glutamate is the most prevalent excitatory neurotransmitter
2. Carbamazepine blocks some glutamate receptors
3. Excess release of glutamate causes neuronal degeneration
4. Aspartate is the main transmitter for neuronal projections from the brainstem to the spinal cord
Select: A = 1,2,3. B = 1. 3. C = 2 , 4 . D= 4 only. E = All
Answer 49-2: A.
There are no known purely aspartate synapses.
Glutamate and aspartate are interconvertible
and likely act at the same receptor. CBZ is
only one of several AEDs which act at least
partly at glutamate receptors. Others include
felbamate, topiramate, and phenobarbital.
(p884)
Question 49-3:
Which of the following statements are true regarding acetylcholine receptors?
1. Sympathetic ganglion receptors are nicotinic
2. Motor endplate receptors are muscarinic
3. Patients with myasthenia have increased acetylcholine receptor turnover causing fewer receptors to be available for binding with acetylcholine
4. Botulinum toxin blocks binding of acetylcholine to the post-synaptic receptors
Select: A = 1. 2. 3. B = 1, 3. C = 2,4, D = 4 only. E = All
Answer 49-3: B
Sympathetic ganglion, motor endplate
receptors, and many CNS receptors are
nicotinic, whereas many CNS receptors, and
most post-ganglionic parasympathetic
receptors are muscarinic. Botulinum toxin.binds to the presynaptic terminal to prevent i release of transmitter. (p878)
Question 49-4:
Which of the following agents are acetylcholinesterase inhibitors?
1. Edrophonium
2. Tacrine
3. Pyridosligmine
4. Donepezil
Select A = 1,2. 3. B = 1,3. C = 2, 4. D = 4 only. E = All
Answer 49-4: E.
All of these agents are acetylcholinesterase
inhibitors, although they differ substantially in
clinical use. Edrophonium (Tensilon) is used
as a diagnostic test for myasthenia gravis.
Pyridostigmine (Mestinon) is used for
symptomatic treatment of myasthenia. Tacrine
(Cognex) and Donepezil (Aricept, are used for
Alzheimer’s disease. (p889)
Question 49-5:
Glutamate and NMDA receptors are involved in which of the following conditions?
I. Memory
2. Neonatal glycine encephalopathy
3. Stroke
4. Migraine
Select: A = 1,2,3. B = 1,3. C = 2, 4. D= 4 only. E= All
Answer 49-5: E.
Glutamate is felt to be implicated in all of
these conditions. NMDA receptors are thought
to be involved in long-term potentiation, an
important experimental model of memory.
Neonatal glycine encephalopathy presents
with hypotonia, seizures, and a burst
suppression pattern on EEG which is thought
to be due to a deficit in a glycine-cleavage
enzyme. Glutamate is thought to be partly
responsible for augmenting the damage
tollowing stroke by its excitotoxic effect after
release. Monosodium glutamate is a common
precipitant of migraine. (p884)
Question 49-6 Parkinsonian symptoms would be produced by a drug which binds to which subset of the dopamine receptors? A. D1 B. D2 C. D3 D. D4
Answer 49-6: B.
Binding to the D2 receptors is thought to
induce parkinsonian fIDdings. Atypical
neuroleptics, which have a much lower
frequency of inducing parkinsonian adverse
effects, bind mainly to the D3 and D4
receptors. (p881)
Question 49-7:
Which of the following statements are true regarding the pharmacology of dopamine in the brain?
1. Metabolized by MAO-A
2. Metabolized by COMT
3. The action of dopamine is ended by enzymatic degradation at the receptor
4. Reserpine depletes dopamine bypreventing reuptake into storage vesicles
Select: A = 1,2,3. B= 1, 3. C = 2,4. D= 4 only. E= All
Answer 49-7: C.
Dopamine is metabolized by COMT and
MAO-B, whereas MAO-A metabolizes
norepinephrine and serotonin. Dopamine is
subjected to reuptake before degradation,
rather than being degraded at the receptor.
Reserpine does prevent reuptake of dopamine
into storage vesicles and initially augments
release, initiating the depletion. (p892)
Question 49-8:
Which of the following statements are true regarding serotonin action and metabolism?
1. Migraine headache is preceded by increased free plasma 5-HT
2. Serotonin is a precursor of melatonin
3. Psychotic features of LSD exposure are thought to be due to binding to the 5-HT2 receptors.
4. Sumatriptan activates the 5-HTI Dreceptors
Select: A = 1. 2, 3. B = 1,3. C= 2.4. D = 4 only. E = All
Answer 49-8: E.
All ofthese statements are true. The psychotic
features of Alzheimer’s disease may also be
related to reduction in 5-HT2 receptors.
Serotonin’s involvement in sleep is complex,
and includes its precursor status for the
synthesis of melatonin, which aids regulation
of circadian rhythm. (p898)
Question 49-9:
Opioid peptides have been shown to have roles in which of the following?
1. Seizures
2. Exercise
3. Pain
4. Drug abuse
Select: A = 1,2,3. B = 1,3. C= 2,4. D = 4 only. E = All
Answer 49-9: E.
Endogenous opioid peptides have been
implicated in all of these. Not only do
exogenous opioid compounds have an
analgesic effect, but also endogenous opioids
have a modulating role in pain transmission
and ultimately paception. with interaction at
multiple levels. Opioids have a complicated
role in seizures. with implications for seizure
generation and neuronal degenetation
following seizures and ischemia. (p906)
Question 49-10:
Which of the following statements is true regarding the role of substance P in nociceptive pathways?
A. Substance P is an inhibitory transmitter in the spinal cord closing the gate to nociceptive transmission
B. Substance P is produced by the motor neurons and sensitized afferent fibers to nociceptive input
C. Substance P is a transmitter in the pain pathways of the dorsal horn of the spinal cord
D. Substance P functions in central nociceptive pathways of the brain and not the spinal cord
Answer 49-10: C
Substance P first became well known for its
role as a transmitter of nociceptive pathways
in the dorsal hom of the spinal cord. Laminae
I and II of the dorsal horn. the most dorsal
layers, are the sites of action of substance P.
Since this early characterization, substance P
has also been found to be involved in
modulation of transmission in the ventral hom
and in the brain. (p907)
