Fig. 3

Exploratory behavior and the animal’s preference for the light measured in the light–dark transition test. A Before initiation of nasal PBS or HDM treatment, mice spent more time in the dark side. B After PBS treatment, control mice maintained a preference for the dark while HDM-sensitized mice spent about the same time in the light and dark chambers, which is unusual considering rodents’ natural aversion to bright spaces. ****p < 0.0001, Mann–Whitney. C, D The time ratio spent in the dark versus the light in individual mice before and after the sensitization was significantly lower in HDM group but not in the control PBS group. **p < 0.01, Wilcoxon paired t-test. E, F The number of transitions (how often the light–dark transition zone was crossed) in individual mice was remarkably higher in the HDM group after sensitization. ***p < 0.001, Wilcoxon paired t-test