Immuno-labeling for TRPV1 at the polymodal receptor recording site where the electrical activity shown in Fig 4 was recorded.
A, bright-field image showing within the white dotted circle the mark left on the corneal surface by the rim of the recording electrode. B, all axons in the field of view were revealed by β-tubulin III-IR (green). C, a TRPV1-IR (red) nerve terminal was located at the recording site. In B and C, the dotted circle approximates the dimensions of the electrode tip at the recording site revealed in A. The scale bar in A–C = 50 μm. D and E, show a 3-dimensional reconstruction of the TRPV1-IR nerve terminal from front (D) and side (E) views. The dashed lines in E approximate the boundaries of the corneal epithelium. The indentation of the epithelium was produced by the recording electrode.