We have all felt the sensation of pain. And we are also all familiar with sleep, a necessary bodily process, has cognitive and physiological functions. While sleep is behaviorally regulated, research shows that poor sleep can actually tamper with our brain's processing of pain. Using fMRI imaging, scientists have now visualized the amplification of the pain signal in the somatosensory cortex of sleep deprived individuals.
The somatosensory cortex is the area of the brain that registers pain stimuli, meaning it tells us where the pain sensation we feel is coming from. Then, the pain signal moves into the insula, the part of the brain which integrates all incoming signals and creates our conscious perception of pain. Following that, the signal is sent along to the nucleus accumbens (NAcc) which plays a major role in decision-making, reward, and pain evaluation.
The study, published last year in the Journal of Neuroscience, found that the activity of the NAcc in sleep deprived individuals is altered: compared to the pain response in people who aren't sleep-deprived, the NAcc dulls incoming pain signals, increases pain-relief seeking behavior and affects decision-making.
A previous study highlighted the increase of opioid consumption in burn patients after just one night of interrupted sleep, which reinforces the idea that sleep and our sensations of pain are closely linked. While research strongly supports the idea that sleep deprivation does increase pain, but exactly how our brains process the interplay of sleep and pain is still being investigated. For instance, the NAcc has broad connectivity with many regions of the brain including the prefrontal cortex, anterior cingulate cortex, and the amygdala (just to name a few). Future research should tease apart the question of “What’s more important: the amount of sleep we get or the quality of sleep?”
But in the meantime, consider counting sheep an aid to resetting our bodies and our brains.