Terence J. Coderre (Pain Mechanisms Laboratory, Clinical Research Institute of Montreal, Canada): "It has become increasingly evident over the past few years that, in addition to a sensitization of peripheral nociceptors, peripheral tissue injury leads to a sensitization of neurons in the central nervous system (CNS). This sensitization is a form of neuronal plasticity that may contribute to the development of persistent pain and hyperalgesia. It has also become evident that excitatory amino acids play a critical role in the development of various forms of neuronal plasticity, including long-term potentiation, neuronal growth, and neurotoxicity. Our studies were aimed at examining the potential involvement of an excitatory amino acid-dependent neuronal plasticity to the development of persistent pain following peripheral tissue injury.
"When injected subcutaneously into a ratUs paw, the chemical irritant formalin produces an acute barrage of C-fiber afferent activity, followed by a prolonged phase of persistent activity in dorsal horn ...
