Mechanical signalling in tissues and its possible role in nociception.

Mechanotransduction is known to play a key role in physiological as well as pathological processes. In the present work, the possibility is discussed that even weak mechanical signals travelling through the extracellular matrix can elicit significant cellular responses, by causing gel/sol transitions and actomyosin contractions. Such mechanical cues can result from both physiological activities, such as the heartbeat, and noxious stimuli to which tissues respond by rearranging the cells' cytoskeleton and remodelling the extracellular matrix. The possibility is explored that such viscoelastic modifications also affect the function of nociceptors, thus modulating pain transmission. Growing evidence indicates that the rearrangement of the axonal cytoskeleton represents a key step in nociception. Hyperalgesia is suggested to result from an exceedingly dynamical state of the nociceptor's cytoskeleton, which would lead to enhanced electrical conduction and synaptic facilitation.