Clinical studies have shown that patients with early-stage Alzheimer's disease who receive a new drug called memantine demonstrate significant cogniti...
GMAT Information and Ideas : (Ideas) Questions
Clinical studies have shown that patients with early-stage Alzheimer's disease who receive a new drug called memantine demonstrate significant cognitive improvement within six months of treatment. Dr. James Chen and his research team theorize that memantine's effectiveness stems from its ability to selectively block overactive NMDA receptors in the brain while preserving normal synaptic function, thereby reducing toxic calcium influx that damages neurons. This mechanism differs from previous Alzheimer's treatments that broadly suppress brain activity.
Which research finding would most strongly challenge alternative explanations for memantine's therapeutic success?
Longitudinal studies reveal that memantine patients maintain cognitive stability for extended periods, while patients receiving earlier Alzheimer's medications show continued decline despite initial symptom management.
Laboratory analysis demonstrates that memantine's therapeutic effects persist even when other neurotransmitter systems are pharmacologically blocked, and brain imaging shows that cognitive improvements correlate specifically with reduced NMDA receptor overactivation rather than with changes in dopamine or serotonin pathways.
Patient surveys indicate higher satisfaction rates with memantine treatment compared to previous medications, with fewer reported side effects and better tolerance during the initial adjustment period.
Comparative effectiveness studies show memantine produces superior outcomes to existing treatments across multiple cognitive assessment measures, establishing its clinical superiority in Alzheimer's management.
Step 1: Decode and Map the Passage
Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| Clinical studies have shown that patients with early-stage Alzheimer's disease who receive a new drug called memantine demonstrate significant cognitive improvement within six months of treatment. |
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| Dr. James Chen and his research team theorize that memantine's effectiveness stems from its ability to selectively block overactive NMDA receptors in the brain while preserving normal synaptic function, thereby reducing toxic calcium influx that damages neurons. |
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| This mechanism differs from previous Alzheimer's treatments that broadly suppress brain activity. |
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Passage Architecture & Core Elements
Main Point: Memantine shows promise for Alzheimer's treatment, with researchers theorizing its success comes from selectively targeting overactive NMDA receptors rather than broadly suppressing brain activity.
Argument Flow: The passage establishes clinical evidence for memantine's effectiveness, then presents Dr. Chen's specific theory about how the drug works through selective NMDA receptor blocking, and concludes by distinguishing this targeted mechanism from previous treatments' broad suppression approach.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- The correct answer should provide evidence that directly supports Dr. Chen's NMDA receptor theory while simultaneously ruling out other possible mechanisms
- We need research that shows the therapeutic effects specifically come from NMDA receptor activity, not from other brain pathways or general effects
- The strongest evidence would demonstrate that when other systems are controlled for or blocked, memantine still works through NMDA receptors specifically
Longitudinal studies reveal that memantine patients maintain cognitive stability for extended periods, while patients receiving earlier Alzheimer's medications show continued decline despite initial symptom management.
✗ Incorrect
- Shows memantine has better long-term outcomes than other medications
- This supports effectiveness but doesn't address WHY it works or challenge alternative explanations for the mechanism of action
Laboratory analysis demonstrates that memantine's therapeutic effects persist even when other neurotransmitter systems are pharmacologically blocked, and brain imaging shows that cognitive improvements correlate specifically with reduced NMDA receptor overactivation rather than with changes in dopamine or serotonin pathways.
✓ Correct
- Provides evidence that effects persist when other neurotransmitter systems are blocked
- Brain imaging shows improvements correlate specifically with reduced NMDA receptor overactivation
- This directly supports Chen's NMDA theory while ruling out dopamine/serotonin pathways
Patient surveys indicate higher satisfaction rates with memantine treatment compared to previous medications, with fewer reported side effects and better tolerance during the initial adjustment period.
✗ Incorrect
- Focuses on patient satisfaction and side effects
- Doesn't address the underlying mechanism at all and has no relevance to challenging alternative explanations for how the drug works
Comparative effectiveness studies show memantine produces superior outcomes to existing treatments across multiple cognitive assessment measures, establishing its clinical superiority in Alzheimer's management.
✗ Incorrect
- Shows memantine is clinically superior to existing treatments
- Like choice A, this supports effectiveness but not the specific mechanism