Week 3 Quiz | 100% Correct
Part A: Neuropharmacology Basics & Neurodegenerative Disorders
Q1: The primary neurochemical deficit in Parkinson's Disease involves which
neurotransmitter in the basal ganglia?
A. Acetylcholine
B. Dopamine [CORRECT]
C. Serotonin
D. GABA
Correct Answer: B
Rationale: Parkinson's Disease is characterized by the progressive degeneration of
dopaminergic neurons in the substantia nigra pars compacta, leading to a dopamine
deficiency in the striatum. This dopaminergic loss disrupts the balance between
dopamine and acetylcholine in the basal ganglia, resulting in the classic motor
symptoms (bradykinesia, rigidity, resting tremor, postural instability). While acetylcholine
(A) is involved in the pathophysiology (relative cholinergic excess), the primary deficit is
dopamine loss. Therapeutic strategies aim to restore dopaminergic activity through
dopamine precursors (levodopa), dopamine agonists, or preventing dopamine
breakdown.
, Q2: A 72-year-old patient with newly diagnosed moderate Alzheimer's Disease is
started on pharmacotherapy. Which medication class is considered first-line treatment
to improve cognitive symptoms by increasing cholinergic activity?
A. NMDA receptor antagonists (e.g., memantine)
B. Cholinesterase inhibitors (e.g., donepezil, rivastigmine) [CORRECT]
C. Dopamine agonists
D. Benzodiazepines
Correct Answer: B
Rationale: A core pathological feature of Alzheimer's Disease is the loss of cholinergic
neurons in the nucleus basalis of Meynert. Cholinesterase inhibitors (donepezil,
rivastigmine, galantamine) work by inhibiting acetylcholinesterase, the enzyme that
breaks down acetylcholine, thereby increasing acetylcholine levels in the synaptic cleft.
This can temporarily improve or stabilize cognitive function, global impression, and
functional performance. Memantine (A) is an NMDA receptor antagonist often used in
moderate-to-severe Alzheimer's or in combination with cholinesterase inhibitors, but it is
not the first-line monotherapy for mild-to-moderate disease. Dopamine agonists (C) are
used for Parkinson's Disease; benzodiazepines (D) are contraindicated due to cognitive
side effects.
Q3: A patient with Parkinson's Disease on levodopa/carbidopa begins experiencing
"wearing-off" phenomena and dyskinesias. The prescriber adds a
catechol-O-methyltransferase (COMT) inhibitor. What is the primary pharmacologic
rationale for this addition?
A. To directly stimulate dopamine receptors