Systolic inhibition of nociceptive responding is moderated by arousal

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Colleges, School and Institutes

Abstract

Inhibition of the nociceptive flexion reflex during systole could be due to activation of the arterial baroreceptors. Physiological arousal, characterized by raised blood pressure, increases afferent activity from the arterial baroreceptors but attenuates the baroreflex. This study examined the effects of arousal on systolic inhibition of the nociceptive flexion reflex in 38 adults. The threshold current to elicit the reflex in the leg was determined, and participants were stimulated at threshold intensity for 12 trials in two conditions: rest (low arousal) and mental arithmetic (high arousal). In each trial, stimulation was delivered 0 ms, 300 ms, or 600 ms after the R-wave of the electrocardiogram. Nociceptive responding was inhibited for stimulation at 300 ms after the R-wave during rest but not mental arithmetic. This moderation of systolic inhibition of nociception could be due to attenuation of the baroreflex with increased arousal.

Details

Original languageEnglish
Pages (from-to)314-9
Number of pages6
JournalPsychophysiology
Volume43
Issue number3
Publication statusPublished - 1 May 2006

Keywords

  • arousal, baroreceptor activation, nociceptive flexion reflex