Figure 5. IL-5 activates Na_V1.8⁺ nodose ganglion neurons.

IL-5 levels in BALFs increased in OVA challenged mice, an effect reversed by QX-314 (100 μM) (A). Transcript profiling of naïve nodose ganglia reveals basal expression of cytokine receptors including IL-5R (B). Cultured nodose ganglion neurons from OVA-exposed mice show a dose-dependent calcium increase (C) in response to IL-5 (0.3–10 μg/ml). Venn diagram shows overlapping populations of KCL⁺IL-5⁺ and AITC or capsaicin responsive neurons (D). IL-5 responsive cells are mainly small and medium size (E) and nearly null in OVA-exposed Na_v1.8-Cre ^+/− DTA^+/− mice (F). IL5 mediated calcium increase absent in 0 external Ca²⁺ (G). Current-clamp recordings of small cells (capacitance <45 pF) showing that IL-5 (1 μg/ml) depolarizing resting membrane potential (RMP) by ~6 mV (H, I; n = 12 cells). The current needed to trigger an action potential (rheobase) is smaller when IL-5 is present (J, K; n = 7 cells). Mean ± S.E.M; Two-tailed unpaired (A–G) and paired (H–K) Student’s t-test (n = 3 biological replicate per group).