Peptide release elicited by a 10 minute exposure to HEPES buffer alone (open bars) or HEPES buffer containing 50 nM capsaicin (Cap; dark bars) is expressed as mean percent total peptide content of cells in each well ± SEM (n = 9-22 wells per condition). GDNF, neurturin (NTN), artemin (ART), or persephin (PSP), at 10 ng/mL, was included in the 10 minutes prior to and throughout capsaicin exposure. Total growth factor exposure time was 20 minutes. Asterisks (*) indicate statistically significant differences in iCGRP release between treatment groups and the no GFL condition using an ANOVA with Dunnett's post-hoc test (p<0.05). In all cases, release stimulated by capsaicin was significantly higher than basal release.