Figure 6. Pcdh10 KO mice show anxiety-related behaviors, impaired fear conditioning, and decreased stress-coping responses. A, Elevated plus maze test. Times spent in the open arm and the closed arm are increased and decreased, respectively, in Pcdh10−/− mice relative to Pcdh10+/+ mice. n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. B, Light/dark transition test. Times spent in the light area and the dark area are increased and decreased, respectively, in Pcdh10−/− mice relative to Pcdh10+/+ mice. The transition number is increased in Pcdh10−/− mice. n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. C, Visual test. Days required to the criterion are similar between Pcdh10+/+ and Pcdh10−/− mice. n = 11 mice for Pcdh10+/+ and 12 for Pcdh10−/−. D, F, Fear conditioning test with Pcdh10+/+ and Pcdh10−/− mice (D) or with Pcdh10+/+ and Pcdh10+/− mice (F). Left, Freezing responses during conditioning on day 1. CS is presented for 30 s, three times (gray shadows). At the end of each CS, a US was given (red). CS, 10-kHz tone; US, 0.3-mA foot shock. Middle, Freezing responses during the contextual test on day 2. Right, Freezing responses during the cued test on day 3. CS is presented at 3–6 min (gray shadow). Freezing responses during the conditioning, contextual, and cued tests are reduced in Pcdh10−/− mice relative to Pcdh10+/+ mice (D). n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. Freezing responses between the second and third foot shocks during the conditioning are slightly reduced in Pcdh10+/− mice relative to Pcdh10+/+ mice (F). n = 5 mice for Pcdh10+/+ and 6 for Pcdh10+/−. E, Hot plate test. The withdrawal latency is similar between Pcdh10+/+ and Pcdh10−/− mice. n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. G, Tail suspension test. Left, Immobility time is measured for 6 min. Right, Cumulative immobility time during the 6-min test session. Immobility time is reduced in Pcdh10−/− mice relative to Pcdh10+/+ mice. n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. H, Forced swim test. Left, Immobility time is measured for 10 min. Right, Cumulative immobility time during the 10-min test session. Immobility time is similar between Pcdh10+/+ and Pcdh10−/− mice. n = 13 mice for Pcdh10+/+ and 12 for Pcdh10−/−. Data are mean ± SEM *p < 0.05, ***p < 0.005; Student's t test (A–C, E, G, right, H, right). *p < 0.05, **p < 0.01, ***p < 0.005; two-way repeated-measures ANOVA followed by the Sidak's test (D, F, G, left, H, left).