Figure 1. Scn1a^+/− mice display hyperactivity, anxiety-like behavior, increased stereotypies, poor nest-building, and impaired social behavior.

In the open field test, Scn1a^+/− mice travel longer distances compared with WT mice (a), spend less time in the center (b), spend more time grooming (e) and circling (f) than WT mice. In the elevated plus maze, Scn1a^+/− mice enter less frequently in the open arms (c) and spend less time in the open arms (d). In (f) one complete turn is counted as one circle, regardless of direction. g, h, Three-chamber experiment. g, Whereas WT mice spend more time in the chamber housing a stranger mouse (M) than the chamber housing an empty cage (E), Scn1a^+/− mice have no preference for either chamber. h, Whereas WT mice spend more time in the chamber housing a novel mouse (M2) than in a chamber housing a familiar mouse (M1), Scn1a^+/− mice have no preference for either chamber. i - l, Social interaction test. i, Scn1a^+/− mice show decreased interaction with a caged stranger mouse when compared with WT mice. j, In a 10-min reciprocal interaction test, pairs of WT and Scn1a^+/− unfamiliar mice had significantly less non-aggressive (Non-A) and aggressive (A) interactions than pairs of WT and WT unfamiliar mice. Aggressive behaviors included attacking, wrestling, and biting the dorsal surface, and non-aggressive behaviors include nose-to-nose sniffing, anogenital sniffing, and grooming. All data shown are means ± s.e.m. from 10 – 12 mice per genotype. *P < 0.05, **P < 0.01, ***P < 0.001. k, Scn1a^+/− mice move significantly less when they encountered the stranger mouse compared to an empty cage, whereas there is no difference in movement for WT. l, Scn1a^+/− mice, but not WT mice, show increased immobilization behavior in the presence of the caged stranger mouse than in the presence of an empty cage.