Gene array analysis to determine the components of neuropathic pain signaling.

The molecular modification of the pain pathway represents one of the major mechanisms underlying neuropathic pain. Recently, gene array studies have been carried out to identify the genes that are regulated at the spinal cord level after peripheral nerve injury. These studies demonstrate that peripheral nerve injury causes marked changes in gene expression in both the dorsal root ganglion (DRG) and the dorsal spinal cord. The markedly regulated molecules include, for example, neuropeptides, receptors, ion channels, signal transduction molecules and synaptic vesicle proteins. Upregulation of the Ca2+ channel alpha2/delta1 subunit, gamma-aminobutyric acid A receptor alpha5 subunit, Na+ channels and nicotinic acetylcholine receptors in the DRG and dorsal spinal cord indicates their potential roles in neuropathic pain control.