EGFR is expressed in DRG-neurons. A) Analysis of EGFR mRNA expression in lysates of DRG and brain from male rats by RT-PCR. RT-PCR shows a DNA-fragment with increasing intensity in dependence of the number (30, 35 and 40) of amplification cycles for DRG (lane 1-3) and brain (lane 6-8). Lane 4 and 9 reaction without reverse transcriptase (-RT) and lane 5 and 10 water control. B) Confocal images of DRG-sections. Left panel EGFR-staining, middle panel EGFR + blocking peptide, right panel secondary antibody control leaving out the primary antibody. C-terminal EGFR antibody blocking peptide was used in a 100× higher concentration than the antibody. C) Confocal images of DRG-cultures. Left panel EGFR-staining, middle panel EGFR + peptide, right panel secondary control. C-terminal EGFR antibody blocking peptide was used in a 100× higher concentration than the antibody. Intensity profiles along the indicated line crossing the cells indicate the plasma membrane staining of the EGFR-antibody. EGFR-C-terminal blocking peptide abolished the plasma membrane EGFR-signal D) QuAM quantified intensity histogram of EGFR-stained cultures (red), EGFR + blocking peptide (blue) and secondary control (black) indicated that EGFR is expressed in all neurons (n = 1874 cell for secondary control, n = 1720 cells EGFR, n = 1705 cells for EGFR + blocking peptide; p < 0.001).