Figure 4.

Overexpression of Ca_V1.2 results in mild anxiolytic behavior in the absence of sensory or motor deficits. (A) Zero maze. Ca_V1.2^Tg+; Syn^Tg+ mice spent significantly more time in the open quadrants as a percentage of total time (5 min) on the elevated zero maze (F_2,71 = 5.149, p = .0053. Significant post hoc comparisons: control × Ca_V1.2^Tg+; Syn^Tg+, p = .0055; Ca_V1.2^Tg+; Syn^Tg− × Ca_V1.2^Tg+; Syn^Tg+, ∗p = .0386; Tukey). (B) Elevated plus maze: Ca_V1.2^Tg+; Syn^Tg+ mice spent more time in the open arms of the elevated plus maze than their control and Ca_V1.2^Tg+; Syn^Tg− littermates (F_2,41 = 9.466, p = .0014. Significant post hoc comparisons: control × Ca_V1.2^Tg+; Syn^Tg+, p = .0017; Ca_V1.2^Tg+; Syn^Tg− × Ca_V1.2^Tg+; Syn^Tg+, ∗p = .0136; Tukey). (C) Open field: mice were placed individually into an open field and allowed to explore for 5 minutes. There were no significant differences between groups in the total distance traveled (F_2,74 = 0.0131, p = .8027) during the trial. (D) Rotarod: mice were placed onto the accelerating rotarod (1–60 rpm over 300 s) once per day for 5 days, and latency to fall was recorded. Across groups, there was a main effect of training day (F_3.469,246.3 = 15.32, p < .0001) but no effect of genotype (F_2,73 = 2.491, p = .0899) and no training day × genotype interaction (F_8,284 = 0.4399, p = .8965). (E) Porsolt forced swim test: all 3 groups of mice exhibited similar amounts of time immobile during the forced swim test (F_2,39 = 1.098, p = .8208). (F) Marble burying test: mice were placed individually into corncob bedding-filled cages that contained 24 marbles and were allowed to explore for 30 minutes. There were no significant differences between groups in the number of marbles buried during the marble burying test (F_2,42 = 0.3991, p = .1646). (G) In order to assess sociability, mice were placed into an arena for 5 minutes with the option to explore either a novel mouse or an inanimate object. There were no significant differences between groups (F_2,37 = 1.110, p = .4265); however, all groups preferred interaction with a novel mouse over the object, as indicated by a positive discrimination ratio (∗p < .05; 1-sample t test). (H) Short-term social memory was tested by giving the mice an option to explore either the mouse that they had previously investigated or an unfamiliar mouse. Similarly to sociability, there were no significant differences between groups (F_2,32 = 0.8612, p = .2552), while all of the groups showed a preference for the novel mouse (∗p < .05; 1-sample t test). All data are presented as mean ± SEM.