TNFR2 mRNA is increased following inflammation in the dorsal root ganglion (DRG). (a) Real-time RT-PCR showed an increase in mRNA of tumour necrosis factor receptor type 2 (TNFR2) (expressed as the ratio of TNFR2 mRNA to 18S mRNA) in the DRG ipsilateral to inflammation (n = 4), reaching five times its original level by 7 days. Contralateral TNFR2 levels increased significantly 7 days after inflammation. (b) In situ mRNA hybridisation in the naive DRG detected no TNFR2 mRNA. (c) In situ hybridisation detected TNFR2 mRNA in small cells of the DRG surrounding neuronal somata in the ipsilateral DRG 7 days after inflammation. (d) High-power magnification of TNFR2-labelled cells in the DRG, showing a perisomal distribution. *P < 0.05, **P < 0.01. CFA, complete Freund's adjuvant.