The development of central nociceptive processing and descending modulation of pain

Newborn mammals display robust responses to noxious or tissue-damaging stimulation. These nociceptive or “pain” responses arise from neural activity at different levels of the central nervous system. Protective reflex movements and physiological reactions mediated by spinal cord and brainstem circuits are essential for the preservation of life and well-being but should not be equated with pain awareness. The unique sensation of pain and its unpleasant, threatening quality requires activity in the cortical and subcortical regions of the brain. These brain regions also have the potential to actively increase or decrease pain experience by exerting top-down control of spinal cord and brainstem nociceptive circuits. This chapter summarizes our current knowledge of the development of central nociceptive pathways in the young mammalian brain and the postnatal maturation of top-down pain control. It aims to provide a scientific, mechanistic understanding of infant and childhood pain experience, and their ability to cope with painful events.