The novel therapeuthic targets in the treatment of chronic pain

Effective treatment for neuropathic pain is still lacking, because of poor understanding of pathological mechanisms at the molecular level. Chronic pain (inflammatory and neuropathic pain) is believed to be caused by aberrant neuronal responses along the pain transmission pathways. Both peripheral and central origins are likely to be involved in chronic pain, although their contribution may be different depending on the various forms of chronic pain. Glial cells have recently been implicated in neuropathic pain. These cells form close interactions with neurons and thus may modulate nociceptive transmission under pathological conditions. We will first examine the recent progress in the role of glia in neuropathic and inflammatory pain, with particular emphasis on microglia. Finally, we will discuss how the study of the interaction between neuronal and microglial mechanisms can open the door to new therapeutic opportunities, designed to act on the mechanisms underlying the disease ("disease-oriented") using natural endogenous substances.