Fig. 1: TRPM8 mediates cold-induced ocular nociception.

a Representative image showing that TRPM8-expressing sensory fibers (green) densely innervate the cornea as revealed by TRPM8-EGFPf in the whole-mount cornea from Trpm8^EGFPf/+ mice. b, c The reflex blinking and eye closing responses to air flow (0.5 L/min) at different temperature in WT (n = 7–10) and Trpm8^−/− (n = 10–13) mice. d Representative video frames showing the opening and closing of the mouse eye (outlined by white dash lines). Red dash lines indicate the width and length of the palpebral fissure. e The representative width/length ratio changes of WT and Trpm8^−/− mice in response to cold air (13 °C). Black arrows indicate reflex blinking responses. f The average width/length ratio of WT mice (n = 7) is significantly lower than that of Trpm8^−/− mice (n = 6) in response to cold air (13 °C). Data are expressed as mean ± s.e.m. Statistical analysis by two tailed Student’s t-test. **P < 0.01; ***P < 0.001. All images shown are representative of three independent experiments using tissues from at least three different mice. Scale bar: 100 µm. Source data are provided as a Source Data file.