Arf4 Regulates Dendritic Spine Development Figure 2. Arf4+/2 mice are not impaired in spatial learning and memory, general locomotor activity, motor coordination, or anxiety behavior. Mice were 4–5 months of age at the time of experimentation (12–13 mice per genotype per sex). (A) Results from Morris water maze test for spatial learning and memory. Graph of escape latency times. Points represent averages of daily trials. HD, hidden platform day (2 trials/session, 2 sessions/day); HD0, first trial on HD1; V, visible platform day (2 trials/session, 2 sessions/day). (B–C) Results from probe trials performed 72 h after the final hidden platform training (Probe 2). Data are presented as percent time spent in the target quadrant versus the average time spent in the other quadrants (B) and number of crossings over the original position of the target platform compared to the number of crossings over the equivalent platform positions in other quadrants (C). (D–F) Results from open field test for general locomotor activity. Data are presented as the total number of infrared beam breaks over the 15-minute testing period (D), ratio of activity in the center of the open field compared to activity in the center plus the periphery (E), and total number of rearings over a 15 minute period (F). CenT, total number of beam breaks in the center; TotT, total number of beam breaks in the center plus periphery. (G) Rotarod test for motor coordination. Rotarod was set at 16RPM and animals were tested during three independent trials, each lasting a maximum of 300 seconds. The average latency to fall is shown over all three trials. (H–I) Results from elevated plus maze test for anxiety. Maze consists of two open arms and two closed arms. The percent time spent by male and female WT and Arf4+/2 mice in the open (H) and closed (I) arms is shown. All data are mean6SEM. * p,0.05, *** p,0.001. doi:10.1371/journal.pone.0046340.g002 of the F1 generation. Mice were backcrossed to the C57Bl6 background for at least 5 generations for all studies, producing both Arf4+/2 and WT mice. C57Bl6 mice were purchased from the Jackson Laboratories. All animal procedures were approved by the Gladstone Institutes and the University of California San Francisco Animal Care and Use Committees. PLOS ONE | www.plosone.org 3 September 2012 | Volume 7 | Issue 9 | e46340