A patient reports chronic pain despite no apparent tissue damage. If descending modulatory pathways from the brainstem are impaired, which consequence follows regarding substance P?

💡 Explanation

Impaired descending modulation disrupts the brainstem's ability to inhibit pain signals. This causes increased substance P release in the dorsal horn of the spinal cord, because substance P is a key neurotransmitter in pain pathways, therefore enhancing pain perception, rather than decreasing release, reducing binding, or enhancing reuptake.

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