PHYSIOPHARMACOLOGICAL ASPECTS OF PATHOLOGICAL PAIN STATES

Recordings in both animals and humans have identified various types of nociceptors. A large number of classification systems have been proposed. For example, in cutaneous tissue in man, the existence of unmyelinated polymodal nociceptors (conduction velocity<2m/sec) activated by mechanical, thermal and chemical stimuli have been clearly established. Similarly Aδ mechanothermal nociceptors and high threshold Aδ mechanoreceptors have been identified. The Aδ and C nociceptors have been clearly demonstrated in