Question 2

The diagram below shows a simplified representation of a cholinergic synapse during synaptic transmission.

Cholinergic Synapse

An investigator tests four different neuroactive drugs in separate experiments to determine their primary mechanism of action:

Drug 1: Blocks the exocytosis of neurotransmitter-containing vesicles.
Drug 2: Inhibits the enzymatic hydrolysis of acetylcholine.
Drug 3: Competitively binds to receptors on the postsynaptic membrane, preventing depolarization.
Drug 4: Blocks the influx of divalent cations that trigger vesicle fusion with the presynaptic membrane.

Which of the following correctly matches each drug to its primary target site (W, X, Y, or Z) in the diagram?

$X\text{Drug 1: } \mathbf{W}; \quad \text{Drug 2: } \mathbf{Z}; \quad \text{Drug 3: } \mathbf{Y}; \quad \text{Drug 4: } \mathbf{X}$

$W\text{Drug 1: } \mathbf{X}; \quad \text{Drug 2: } \mathbf{Z}; \quad \text{Drug 3: } \mathbf{Y}; \quad \text{Drug 4: } \mathbf{W}$

$W\text{Drug 1: } \mathbf{X}; \quad \text{Drug 2: } \mathbf{Y}; \quad \text{Drug 3: } \mathbf{Z}; \quad \text{Drug 4: } \mathbf{W}$

$X\text{Drug 1: } \mathbf{W}; \quad \text{Drug 2: } \mathbf{Y}; \quad \text{Drug 3: } \mathbf{Z}; \quad \text{Drug 4: } \mathbf{X}$