Figure 5. The excitatory effect of leptin on mucosal afferents from 20-week-old standard laboratory diet (SLD) mice is conveyed through phopholipase C (PLC)-mediated activation of a canonical transient receptor potential cation (TRPC) channel and therefore not affected by age.

A Single fibre recording stimulus–response curves of mucosal receptors to mucosal stroking in SLD (Aa–f, n= 5) before ○ and after exposure to second messenger inhibitors (a: AG490 – 5 μm; b: wortmannin – 5 nm; c: cilostamide – 5 μm; d: 2-APB – 30 μm; e: U73122 – 10 μm; f: iberiotoxin – 100 nm) □, and in the presence of the respective second messenger inhibitor and leptin 10 nmΔ. ***P < 0.001 vs. control (leptin effect: two-way ANOVA). Data are expressed as mean ± SEM. B, schematic showing proposed signal transduction used by leptin to exert potentiation.