Behavioral responses of B6 R6/2 transgenic and wildtype mice across 4 ages in the open-field test.

<p>(<b>A</b>) Exploratory activity as measured by total distance traveled in an open-field. (<b>B</b>) Rearing behavior as measured by vertical activity (beam interruptions). In both <b>A</b> and <b>B</b>, ‘<i>a</i>’ represents that R6/2 mice are significantly less active than wildtype littermates at 6, 8 and 10 weeks of age. ‘<i>b</i>’ represents that 8 and 10 week old R6/2 mice are less active than 4 and 6 week old R6/2 mice. Wildtype mice increase in activity from 6 to 8 weeks of age. (<b>C</b>) Anxiety-like responses as measured by the center∶total distance ratio. ‘*’ represents that overall B6 R6/2 transgenic mice spend less of their exploration in the center of the open-field relative to wildtype mice. All p-values≤0.022 by three-way ANOVA and simple effects analysis.