The Representation of Nociception and Pain in the Developing Brain

Pain is a fundamental human experience, but how does it begin? Noxious stimuli elicit strong behavioral and physiological responses, even in the youngest newborns, reflecting early subcortical engagement, but the actual experience of pain requires higher cortical processes. This review summarizes current knowledge on how pain associated with tissue injury is represented in the newborn brain. It explores the nature of nociceptive input to the infant brain, the role of immature cortical networks in interpreting this input, and the influence of biological and external factors on these mechanisms. We outline current methods for recording infant brain activity during clinical tissue-damaging procedures, review collected data, and address common misconceptions in the field. We also discuss the differential maturation of sensory, emotional, and cognitive brain systems involved in pain, and propose a model of how the representation of pain evolves as the underlying neural networks develop.