KCl induces pRII-increase predominantly in nociceptive neurons . (A) Dose–response curve of pRII intensity in mouse DRG neurons exposed to KCl (0–80 mM, EC₅₀ = 10 mM) for 3 min. Data are means ± SEM; n = 4 independent experiments; >2,000 neurons/condition; two-way ANOVA with Bonferroni’s test; *, P < 0.05; ***, P < 0.001 indicate significance levels between baseline and stimulated conditions. (B) Cell density plots of cultured rat DRG neurons labeled for pRII and subgroup markers RIIβ, Na_V1.8, CGRP, and NF200. The cells were stimulated with KCl (40 mM, lower panel) or buffer (Ctrl, upper panel) for 3 min to activate PKA-II. Dashed lines indicate gating thresholds used to calculate the percentage of cells in the respective quadrant. Single-cell data of >10,000 neurons per plot from one experiment with pooled cells from n = 3 rats are shown. (C) Marker intensity distributions used to determine the gating thresholds for the subgroup analysis. (D) Quantification pRII intensity and responding pRII(+) neurons in marker-negative and marker-positive neurons from the experiment shown in B and C. Each data point represents the mean of a single culture well.