Fig. 3

Knockout of Vrk2 leads to depressive-like behaviors in mice. A knockout efficiency of Vrk2 in the hippocampus. n = 3 mice/group. P = 0.000047. B Open field test. No significant difference was seen in the total distance (P = 0.576) and the central exploration time (P = 0.217) between Vrk2^+/+ and Vrk2^−/− mice. Vrk2^+/+, n = 12. Vrk2^−/−, n = 14. C Rotarod test. There was no difference in latency time (P = 0.932) between Vrk2^+/+ and Vrk2^−/− mice. Vrk2^+/+, n = 12. Vrk2^−/−, n = 14. D Elevated plus maze. The proportion of distance (P = 0.0640) covered by Vrk2^−/− mice in the open arm was trending downward compared with Vrk2^+/+ mice, but there was no difference in the amount of time spent there (P = 0.258). Vrk2^+/+, n = 12. Vrk2^−/−, n = 14. E Sucrose preference test. Vrk2^+/+, n = 11. Vrk2^−/−, n = 12. P = 0.265. F Tail suspension test. The immobility time (P = 0.438) was not different, but the curling time (P = 0.0016) was significantly decreased in Vrk2^−/− mice. Vrk2^+/+, n = 11. Vrk2^−/−, n = 14. G Experimental timeline and schematic diagram of ventral hippocampal virus injection. H Rotarod test. Vrk2^+/+ + ctrl, n = 8; Vrk2^−/− + ctrl, n = 10; Vrk2^+/+ + Vrk2, n = 7; Vrk2^−/− + Vrk2, n = 10. Vrk2^+/+ + ctrl vs. Vrk2^−/− + ctrl, P = 0.380; Vrk2^+/+ + ctrl vs. Vrk2^−/− + Vrk2, P = 0.582; Vrk2^−/− + ctrl vs. Vrk2^−/− + Vrk2, P = 0.135. I Tail suspension test. Vrk2^−/− + Vrk2 mice showed a considerably greater curling time compared with Vrk2^−/− + ctrl mice (Vrk2^+/+ + ctrl vs. Vrk2^−/− + ctrl, P = 0.0229; Vrk2^+/+ + ctrl vs. Vrk2^−/− + Vrk2, P = 0.452; Vrk2^−/− + ctrl vs. Vrk2^−/− + Vrk2, P = 0.0022). Vrk2^+/+ + ctrl, n = 8; Vrk2^−/− + ctrl, n = 10; Vrk2^+/+ + Vrk2, n = 7; Vrk2^−/− + Vrk2, n = 10. Two-tailed t-test for A–F. One-way ANOVA for H and I. ^#P < 0.1, *P < 0.05, **P < 0.01, ***P < 0.001. Error bars indicate mean ± SD