If a patient reports chronic pain despite opioid treatment following a spinal cord injury, which phenomenon explains the reduced analgesic effect via descending modulation?

💡 Explanation

Nociceptor sensitization leading to wind-up potentiation explains reduced opioid analgesia because persistent nociceptor activation alters spinal cord neuron excitability, thereby increasing pain signaling despite opioid administration. Therefore, the correct answer is C, rather than increased endorphin receptors or GABAergic pathways, which would enhance analgesia.

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