The present study investigates the effects of the NMDA receptor antagonist S-(+)-ketamine on perception and processing of painful heat stimuli. Healthy volunteers rated pain intensity and unpleasantness on a VAS rating scale during placebo administration and 3 different ketamine doses. Changes in pain-induced cerebral activations were investigated using fMRI. Pain unpleasantness declined as ketamine dosage was increased. Pain intensity also decreased with increasing ketamine dosage, but to a lesser extent. Analysis of dose-dependent ketamine effects on pain processing showed a decreasing activation of the secondary somatosensory cortex (S2) and anterior cingulate cortex (ACC). These findings underline the potency of ketamine in modulating affective pain processing.
«The present study investigates the effects of the NMDA receptor antagonist S-(+)-ketamine on perception and processing of painful heat stimuli. Healthy volunteers rated pain intensity and unpleasantness on a VAS rating scale during placebo administration and 3 different ketamine doses. Changes in pain-induced cerebral activations were investigated using fMRI. Pain unpleasantness declined as ketamine dosage was increased. Pain intensity also decreased with increasing ketamine dosage, but to a les...
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