Influence of Body Position on Cortical Pain-Related Somatosensory Processing: An ERP Study

摘要: Background Despite the consistent information available on physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge possible perceptual-cortical alterations is still poor. The present study investigated effects of 2-h head-down rest subjective and cortical responses elicited electrical, pain-related somatosensory stimulation. Methodology/Principal Findings Twenty male subjects were randomly assigned to two groups, (BR) or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials stimuli administered left wrist divided into four conditions: painless condition, pain threshold, 30% above below threshold. Subjective ratings collected during EEG session showed significantly reduced perception in BR compared Control group. Statistical analysis electrode clusters sLORETA source revealed, controls, P1 component (40–50 ms) right cortex, whereas it was bilateral differently located Controls' N1 (80–90 had widespread hemisphere activation, involving also anterior cingulate, group primary cortex activation. P2 (190–220 larger left-central locations Controls with group. Conclusions/Significance Head-down associated an overall decrease sensitivity altered network outside cortex. Results have implications not only for astronauts' health spaceflight risks, but clinical aspects detection bedridden patients at risk fatal undetected complications.