Transcriptional changes in sensory ganglion associated with primary afferent collateral sprouting in spared dermatome model

In this study, we sought to identify gene expression changes in PACS using 20 Affymetrix Rat Genome 230 2.0 microarrays. The experiments were designed to discover global gene expression changes in non-injured DRG neurons undergoing PACS. T11 DRG neurons remained intact and undergo PACS after the cutaneous nerves of the adjacent segments (T9, T10, T12, and T13) were injured and regeneration of those injured nerves prevented by ligation. Thus, the T9, T10, T12, and T13 dermatomes were denervated, but the T11 dermatome remained intact. Axons of the T11dermatome (and thus housed in the T11 dorsal root ganglion (DRG)), extended new branches to innervate the T9, T10, T12, and T13 dermatomes. N.B.: This is NOT a spared root experiment. ALL spinal roots were non-injured. Peripheral nerves were used.