Fig. 2

IgE-IC directly activates trigeminal sensory neurons through FcεRIα in vitro. A Representative traces of Ca²⁺ responses induced by IgE-IC (0.1 μg/ml, 30 s), capsaicin (Cap; 1 μM, 10 s), and KCl (50 mM, 10 s) in trigeminal neurons from FcεRIα^+/+ (left) and global FcεRIα^–/– (right) mice. B Quantitative analysis showed that IgE-IC evoked Ca 2⁺ responses in a larger proportion of small-diameter (< 25 μm) trigeminal neurons from FcεRIα^+/+ mice than those from FcεRIα^–/– mice. ****P < 0.0001 vs. FcεRIα^+/+, χ² test. No significance was detected between FcεRIα^+/+ mice and FcεRIα^–/– mice for middle- (25–35 μm) and large-diameter (> 35 μm) trigeminal neurons