- A A steady, progressive decrease in perceived pain intensity over repeated identical stimulation events during normal conditions
- B Progressive increase in dorsal horn neuron response due to NMDA receptor activation and substance P release (central sensitization)
- C Little measurable change in dorsal horn neuron firing rate observed over an extended period of time as generally observed in typical laboratory settings
- D Sensitization restricted mainly to peripheral nociceptor nerve terminals, rarely reaching the spinal cord region under usual circumstances
Correct answer: B. Progressive increase in dorsal horn neuron response due to NMDA receptor activation and substance P release (central sensitization)
Explanation: Wind-up: repeated C-fiber stimulation causes progressive increase in dorsal horn WDR neuron firing. Mediated by temporal summation of NMDA activation and substance P. Contributes to chronic pain sensitization.
Concept context
Brain, spinal cord, neurons, reflex arcs, and sense organs.