Figure 1. Capsaicin induced sparklets in whole-cell voltage clamped dorsal root ganglion cells loaded with Fluo-4.
(A) Images of immobile sparklet (white circle) in dorsal root ganglion cell at time points when inactive (1) and active (2) with corresponding intensity trace below (see Video 1). (B) Moving sparklet recorded for 5.6 s in dorsal root ganglion cell (see Video 2). Inset is of sparklet trace magnified fivefold. Inset scale bar is 1 µm. All other scale bars are 5 µm. (C) Mean fluorescence intensity () and (D) open probability (Popen) of dorsal root ganglion sparklets (N = 5; 3 cells) in Figure 1—figure supplement 1 A–E. Cut-off for ‘open’ is when intensity (ΔF/F0) exceeds 0.05.
Figure 1—figure supplement 1. All points histogram of immobile sparklets in dorsal root ganglion cells (N = 5).
Figure 1—figure supplement 2. Dose-response relation for activation TRPV1 channels in isolated dorsal root ganglion neurons by capsaicin.
Points are the means from four cells, and the currents for each cell were normalized by the current measured at 300 nM capsaicin. Error bars are standard error of the mean. Data is fitted to a Hill curve with Hill coefficient of 2.2. Blue arrow indicates the data point for 100 nM capsaicin.
Figure 1—figure supplement 3. Increase in fluorescence intensity due to Ca2+ influx into F11 cell transfected with TRPV1-tagRFP, with Fluo-4 introduced via the whole-cell patch pipette.
The two images of the F11 cell are a projection of bright pixels in a set of images before capsaicin was added (left) followed by a projection of bright pixels in a set of images after capsaicin was added (right) (see Video 5). Scale bars are 5 µm.