Peripheral and central mechanisms of pain generation

[Guest guest]

Handb Exp Pharmacol. 2007;(177):3-28.

Peripheral and central mechanisms of pain generation.

Schaible HG.

Institut fur Physiologie/Neurophysiologie, Teichgraben 8, 07740

Jena, Germany.

Pain research has uncovered important neuronal mechanisms that

underlie clinically relevant pain states such as inflammatory and

neuropathic pain. Importantly, both the peripheral and the central

nociceptive system contribute significantly to the generation of

pain upon inflammation and nerve injury. Peripheral nociceptors are

sensitized during inflammation, and peripheral nerve fibres develop

ectopic discharges upon nerve injury or disease.

As a consequence a complex neuronal response is evoked in the spinal

cord where neurons become hyperexcitable, and a new balance is set

between excitation and inhibition. The spinal processes are

significantly influenced by brain stem circuits that inhibit or

facilitate spinal nociceptive processing. Numerous mechanisms are

involved in peripheral and central nociceptive processes including

rapid functional changes of signalling and long-term regulatory

changes such as up-regulation of mediator/receptor systems.

Conscious pain is generated by thalamocortical networks that produce

both sensory discriminative and affective components of the pain

response.