Descending Modulation of Nociception
Nociceptive modulation; Pain modulation; Endogenous analgesia system; Descending pain modulation
Descending pain modulation encompasses pathways that descend from the forebrain and brainstem to the spinal cord and trigeminal sensory complex to modify incoming somatosensory information so that the perception of and reactions to somatosensory stimuli are altered, resulting in either less or more pain.
That mammalian sensory systems do not record the world faithfully is so obvious as to border on the cliché. Visual, auditory and somatosensory illusions are clear evidence that what we perceive differs from what exists externally. In the case of pain, a function absolutely critical to survival, it is remarkable that a given stimulus (or lack of stimulus) does not reliably evoke a predictable sensation. Under some circumstances, sensory perception is dominated by ascending nociceptive pathways as one may expect;