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Question #46556
The Question
A chronic user of heroin (diacetylmorphine) abruptly discontinues its use, precipitating a severe withdrawal syndrome characterized by anxiety, shakiness, and tachycardia. Based on the principles of synaptic transmission and neuroadaptation, which of the following best explains the physiological basis of this hyper-excitability?
Options
- A.
Agonist-induced downregulation of opioid receptors, resulting in uncompensated excitatory synaptic activity when the exogenous depressant is removed.
- B.
Chronic competitive inhibition of endogenous endorphins, leading to a sudden surge of inhibitory signals upon drug withdrawal.
- C.
Compensatory upregulation of opioid receptors in the central nervous system due to the continuous presence of the depressant drug.
- D.
Depletion of excitatory neurotransmitters in the presynaptic neurons due to prolonged metabolic suppression by diacetylmorphine.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Neurotransmitters|Opioids|Dopamine_Receptor_Internalization
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the direction of receptor adaptation (upregulation vs. downregulation) and fail to link the depressant nature of opioids with the rebound hyper-excitability of withdrawal.
A common misconception is that the drug 'depletes' brain chemicals (Option D) or causes an 'upregulation' to fight the drug (Option C).
The key is understanding that the brain removes its own physiological 'brakes' (downregulates inhibitory receptors) in response to the artificial brakes (heroin), leaving it overactive when the drug is suddenly withdrawn.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Drug Withdrawal Syndrome |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |