Fig. 3: LAKI controls pain behavior in freely moving mice.

a Representation of the experimental procedures (created with BioRender.com). b Schematic of experimental behavioral assays. Black arrows represent the injection or topical application of saline solution or LAKI. Magenta arrows represent the pulse of light at 365 nm. Green arrows represent the measurement of nocifensive behavior or thermal and mechanical sensitivity. The red arrow represents extracellular in vivo recording. c Bar graph summarizing the average of nocifensive behavior elicited by mice after ocular application of either saline or LAKI (100 µM, 5 µL) solution preceded or not by a 20 s illumination pulse (<1 mW/mm²) at 365 nm (magenta). n was obtained from three independent experiments. Statistical significance was determined by Poisson GLM followed by Bonferroni’s post-test (***p < 0.001). d Bar graph showing the average of nocifensive behavior, making the distinction between scratching and wiping behavior, elicited by mice after topical application of either saline or LAKI (100 µM, 5 µL) solution preceded or not by a 20 s illumination at 365 nm (magenta). n was obtained from three independent experiments. Statistical significance was determined by Poisson GLM followed by Bonferroni’s post-test (**p = 0.00564 for scratching, **p = 0.0035 for wiping). e Bar graph summarizing the average of the thermal paw withdrawal latency of mice injected either with saline solution or with LAKI (100 µM, 15 µL) before and after 20 s illumination at 365 nm (magenta). n was obtained from one experiment. Statistical significance was determined by two-way ANOVA with repeated measures followed by Holm–Sidak’s post-test (***p = 0.0002). f Graph summarizing the average of the relative paw withdrawal latency of mice injected with LAKI (100 µM, 15 µL) relative to mice injected with saline solution. n was obtained from one experiment. Statistical significance was determined by a mixed-effects model with repeated measures followed by Holm–Sidak’s post-test (**p = 0.0074 and p = 0.0017 respectively for first and second illumination at 365 nm). g Bar graph summarizing the average of the thermal paw withdrawal latency of mice injected either with LAKI (100 µM, 15 µL) or with LAKI plus ML67.33 (100 µM) after 20 s illumination at 365 nm. n was obtained from one experiment. Statistical significance was determined by a mixed-effects model with repeated measures followed by Holm–Sidak’s post-test (**p = 0.0062). h Bar graph summarizing the average of the relative paw withdrawal latency at 0, 3, 5, and 7 days post-injection after 20 s illumination at 365 nm (magenta). n was obtained from one experiment. Statistical significance was determined by a mixed-effects model with repeated measures followed by Holm–Sidak’s post-test (*p = 0.0233, p = 0.0104, p = 0.0469, and p = 0.0469 respectively for Days 0, 3, 5, and 7). Data were represented as mean ± SEM. The numbers of mice are indicated in parentheses on the graph.