Figure 6

Activity recording of orexin neurons using fiber photometry during perception of noxious stimuli.

(A) Mechanical noxious stimuli were applied to conscious or anesthetized mice. Mice were given mechanical stimulation (maximum strength: 100, 200 and 300 g) to the tail using forceps equipped with a force sensor at the tip. (B) Representative traces of fluorescence intensity changes evoked by mechanical stimulation in mice expressing G-CaMP6 exclusively in orexin neurons (C) Averaged mechanical stimulation (red) and fluorescence intensity change (blue) are shown as the mean ± SEM in awake and anesthetized mice (n = 4–6 mice). (D) % increases in fluorescence intensity induced by mechanical stimulation (*P < 0.05, one-way ANOVA followed by Dunn’s multiple comparison test). (E) Noxious heat stimuli were applied to conscious or anesthetized mice. Mice were given heat stimulation (maximum heat: 50 and 60 °C) to the plantar surface of the paw. (F) Representative traces of fluorescence intensity changes evoked by heat stimulation in mice expressing G-CaMP6 exclusively in orexin neurons. (G) Averaged heat stimulation (red) and fluorescence intensity change (blue) are shown as the mean ± SEM in awake and anesthetized mice (n = 5–7 mice). (H) % increase in fluorescence intensity induced by heat stimuli (*p < 0.05, **p < 0.01, one-way ANOVA followed by Dunn’s multiple comparison test).