Figure 6.
The TRPA1 channel mediates WIN and AM1241 responses in TG neurons. A–D, Knockdown of TRPA1 in TG neurons with rat TRPA1-specific siRNAs ALab, AA, or AB oblates positive control (MO 20 μm) responses (A), as well as AM1241 (30 μm; C) and WIN (25 μm; D), but not CAP (0.3 μm; B) responses measured as internal Ca2+ accumulation (Δ[Ca2+]i). Treatments of TG neurons with Drosophila TRPA1-specific (ADr) and scrambled (#1) siRNAs have no effects on MO, CAP, WIN, and AM1241 responses (A–D). All data were compared with mock (None) transfected TG neurons. CAP application was for 1 min, MO for 2 min, and WIN and AM1241 for 4 min each. Types of siRNA transfection are indicated on x-axis. Data were collected from all neurons (i.e., both transfected and untransfected; marked “All”) or from only transfected neurons (marked “transf”) that were identified by ALab conjugated with Alexa Fluor 488. Together, one round of siRNA transfection was performed and TG neurons were cultured for 3 d. The numbers of responsive cells over the total number of studied cells are indicated within the columns. E, F, MO (25 μm; E)-, WIN (25 μm; F)-, and CAP (50 nm; E)-activated accumulation of [Ca2+]i in TG neurons from WT and TRPA1 KO mice. Indicated drugs were separately delivered to at least 60 neurons. The numbers of responsive neurons are indicated within bars. Mouse lines are also noted. G, This panel shows CAP and WIN treatments of two groups of TG neurons (BrF) transfected with Alexa Fluor 488-labeled ALab (ALab-siRNA). The yellow arrows show ALab containing neurons that are responsive to CAP. The red arrow indicates a neuron that is untransfected and activated by WIN, whereas transfected neurons are unresponsive to WIN application. Error bars are SEM. **p < 0.01; ***p < 0.001.