Figure 7.

Modulation of prodynorphin (Pdyn), proenkephalin (Penk), and galanin (Gal) mRNA expression in the DRG after sciatic nerve transection or spinal nerve transection or spinal nerve ligation. (A-C) Sciatic transcetion. The sciatic nerve was transected and L4 and L5 DRGs were collected at 0d, 1d, 3d, 10d, 30d, and 90d after the axotomy. Both Pdyn and Gal were significantly elevated in the dorsal root ganglia, whereas Penk was significantly decreased. Statistics were performed in MAGIC with experimental time points compared to the naÿve control. The contralateral side is shown, but statistics were not performed for ipsilateral versus contralateral at each time point, because the contralateral sample for some time points were single replicates (10d, 30d, 90d). In the ipsilateral time points, some error bars are smaller than the marker size (not shown). (D-F) Molecular meta-analysis of spinal nerve injury studies. The experimental axotomy findings in A-C were also investigated by realigning and reanalyzing 4 RNA-Seq datasets from the SRA database from previously published reports. Also included is an examination the transcriptional effects of carrageenan inflammation on DRG gene expression. Statistics were performed to examine the overall statistical effect between all axotomy samples and all controls in aggregate (see methods). All 3 genes were significant when considering the data from all 5 datasets in aggregate. In contrast, carrageenan did not alter DRG expression of Pdyn, Penk, or Gal. Error bars show the standard error of the mean.