Figure 4.

A DRG level intervention is effective early after DRG inflammation, but not starting 1 week later. Mechanical hypersensitivity (von Frey test) induced by DRG inflammation was increased by local inflammation of the DRG. This was greatly reduced by locally perfusing the DRG with riluzole, a blocker of persistent Na current, for 7 days starting at the time of inflammation (red; data adapted from reference [16]). DRG perfusion method was as shown in Figure 1. Perfusion with vehicle (ACSF; artificial cerebrospinal fluid, black symbols) was ineffective. However, riluzole perfusion starting 7 days after inflammation was ineffective (green symbols; unpublished data from our laboratory. N = 6 rats per group. No significant differences from the ACSF group were observed on any day by repeated measures ANOVA).