Immuno-labeling for TRPV1 at a cold thermoreceptor recording site.
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, while TRPV1-IR axons (red) were observed within the field of view, those enclosed by the recording electrode were not immunoreactive for this protein. 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.