Figure 2. PLpro activates upper airway-innervating neurons in vivo.

a, Schematic of in vivo imaging preparation. b, Image of trigeminal ganglion overlaid with the regions of interest of neurons that respond to intranasal perfusion (10 μL) of vehicle (Veh), 10 μM PLpro, and 100 μM capsaicin (Cap). c, Representative calcium transients in response to intranasal perfusion of Veh, 10 μM PLpro, 1 mM AITC, 100 μM Cap. d, Venn diagram of neurons responsive to vehicle (112/307) and PLpro (116/307), n=307 neurons from 6 mice. PLpro activates a subset of vehicle-sensitive neurons (32/112). e, Percent of recorded neurons that respond to each stimulus. f, Vehicle and PLpro activate a subset of TRPV1+ (capsaicin-responsive) neurons and TRPA1+ (AITC-responsive) neurons. Top Left, percent of TRPV1+ neurons responsive to vehicle only: 13.8%, both vehicle and PLpro: 9.7%, PLpro only: 15.9%, n=145 neurons from 6 mice; Top Right, percent of TRPV1+ neurons responsive to the first delivery of vehicle only: 17.8%, both first and second (Veh₂) deliveries of vehicle: 2.7%, second delivery of vehicle only: 2.7%, n=73 neurons from 3 mice, Chi-square test χ² = 112.5, df = 3, p<0.0001. Bottom Left, percent of TRPA1+ neurons responsive to vehicle only: 18.4%, both vehicle and PLpro: 17.2%, PLpro only: 18.4%, n=87 neurons from 4 mice; Bottom Right, percent of TRPA1+ neurons responsive to the first delivery of vehicle only: 25.0%, both deliveries of vehicle: 27.3%, second delivery of vehicle only: 9.1%, n=44 neurons from 3 mice, Chi-square test χ² = 14.2, df = 3, p = 0.003.