The KCl-induced increase of pRII intensity cannot be altered by inhibition of adenylycyclases or phosphodiesterases. (A) Expression pattern of AC isoforms in adult rat DRGs determined by RNA-seq (Isensee et al., 2014b). (B–I) Effect of the AC inhibitors NB001, ST034307, SQ22536, and NKY80 (100 µM each, 30-min pretreatment) on the pRII increase induced by KCl (40 mM) or 5-HT (250 nM). (J and K) Effect of the phosphodiesterase inhibitor IBMX (100 µM, 30-min pretreatment) on the pRII increase induced by 5-HT (250 nM) or KCl (40 mM). The data shown are not normalized to the baseline difference due to IBMX treatment alone. Data in A are means ± SD, n = 6 replicates. Values in B–K represent means ± SEM; n = 3–4 experiments; >2,000 neurons/condition; two-way ANOVA with Bonferroni’s test; §§, P < 0.01; §§§, P < 0.001 indicate significance levels between 5-HT-induced pRII signals in the absence or presence of an inhibitor.