Séminaire COSY : "Secondary hyperalgesia : From phenomenology to underlying mechanisms."

Ce séminaire (invitation) se déroulera dans la salle de Séminaire Martin V 42B de 12h30 à 13h30 sur le campus de Louvain-en-Woluwé (UCL) et s'inscrit dans le cadre du cycle de séminaires 2014-2015 organisé par le pôle COSY.

Abstract : Tissue injury is often accompanied by increased pain sensitivity (i.e. hyperalgesia) that is present in the injured skin (referred to as primary hyperalgesia) but also spreads to the surrounding uninjured skin (referred to as secondary hyperalgesia). Since the first systematic observations about the nature of secondary hyperalgesia have been published there is an ongoing debate about the origin of its underlying mechanism. There are two dominant hypotheses. The first hypothesis, which I refer to as the “peripheral hypothesis”, states that secondary hyperalgesia is mediated by a sensitization of peripheral nerve endings of a special class of unmeyelinated nociceptors (C fibers). The second hypothesis, which I refer to as the “central hypothesis” states that secondary hyperalgesia is mediated by myelinated nociceptors (A fibers) which input is amplified at the level of the central nervous system (spinal cord). In this talk I will discuss the psychophysical and neurophysiological evidence for both hypotheses. Moreover, I will show some recent results, which were collected in our lab, about the induction and characteristics of secondary hyperalgesia by means of an alternative hyperalgesia- inducing model. Finally, I will show and discuss some new results regarding a potential brain correlate of secondary hyperalgesia.