Kif4 ^Mut/Y mice exhibit anxiety, anti-depression and intellectual disability. (A) The heatmap of the occupancy of individual mice in OFT. A warmer color represents more time spent (red > yellow > green > blue), and red rectangles are put at the central zones in the fields. (B–E) The results of OFT. Total distances that mice ran during tests (B), cumulative durations in the edge zone (C) or the central zone (D), and in-zone frequencies to the central zone (E) are represented. Data are presented as mean ± SEM (n = 12 mouse pairs). ns, P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001 (Student’s t tests). (F and G) The results of the EPM test. The number of entries into the open arm (F) and the cumulative durations mice spent in the open arm (G) were decreased in the Kif4^Mut/Y mice. Data are presented as mean ± SEM (n = 12 mouse pairs). **P < 0.01, (Student’s t tests). (H) Schematic illustration showing the schedule of novel objective recognition test (NORT). (I) The results of OLT and NORT. The discrimination index is calculated from the time difference between two events divided by the sum of that time. Positive values indicate that the mouse spent more time investigating the novel object or location. Note that Kif4^Mut/Y mice had a value of ∼0, indicating a memory dysfunction phenotype. Data are presented as mean ± SEM (n = 12 mouse pairs). ns, P > 0.05, ***P < 0.001, ****P < 0.0001 (two-way ANOVA). (J) The results of FCT. Total freezing durations were recorded. Kif4^Mut/Y mice exhibited shorter freezing time at both Day 1 and 7. Data are presented as mean ± SEM (n = 12 mouse pairs). ****P < 0.0001 (two-way ANOVA).