Understanding pain: How is pain processed in healthy humans? (original) (raw)

The Determinants of Pain Revisited: Coordinates in Sensory Space

Pain Research and Management

Ron Melzack recognized that the gate control hypothesis of 1965 was incomplete. This led to the publication of a book chapter that would someday be referred to by some as 'the classical view' of pain mechanisms. However, this paper presented some conceptual problems for research on pain mechanisms by using the term 'motivational-affective' to define a determinant of pain. To facilitate research and eventually improve practice, the determinants of pain need to be identified and quantified more clearly. In the present article, three critical dimensions of sensory experience that define pain and related sensory experiences are identified: sensory salience, affect and motivational dominance. The authors show that each of these dimensions can be measured and are mediated by specific neurophysiological mechanisms. Pain and other somatic sensations emerge from the conjoint actions of these neurophysiological systems and fall within unambiguously defined coordinates of the t...

The anatomy and physiology of pain

Pain is an unpleasant experience which results from both physical and psychological responses to injury. A complex set of pathways transmits pain messages from the periphery to the central nervous system, where control occurs from higher centres. Primary afferent pain fibres synapse with second-order neurons in the dorsal horn of the spinal cord. Ascending spinothalamic and spinoreticular tracts convey pain up to the brain, where pain signals are processed by the thalamus and sent to the cortex. Descending tracts, via the midbrain periaquaductal grey and nucleus raphe magnus, have a role in pain modulation. When nerves are damaged, neuropathic pain results and various mechanisms have been proposed for how this takes place. These mechanisms involve both peripheral and central sensitization.

Anatomy, physiology and pharmacology of pain

Surgery (oxford), 2006

Pain is a complex emotional experience arising from integrated processing of nociceptive input subject to inhibitory and excitatory modulatory influences at multiple levels of the neuraxis. Transmembrane protein ion channels transduce mechanical, thermal and chemical tissue injury into electrophysiological signals that are transmitted to supraspinal structures via multiple synapses that exhibit neuroplasticity dependent upon coincident neuronal and glial activation. There are therefore multiple potential pharmacological targets and the complexity of pain perception necessitates multimodal management.