W-maze design, experimental paradigm and training for mice. A, Schematic diagrams of W-maze. B, Schematic diagram of mouse dieting plan. Mouse ad libitum body weight and after food reduction when animals body weight is 85% ad libitum weight (top). Body weight of animals from beginning of diet until first day of training (bottom). C, Schematic diagrams of W-maze training program. Days 1–4, single arm (left) retrieval of rewards at each end. Days 4–8, two-arms alternating (center) retrieval of rewards at center and outbound arm (switching outbound arm each days 4–8). Day 8 to 85% accuracy (right) retrieval of W-maze tests as described in B. D, Accuracy over three arm training of inbound (gray) and outbound (red) of animals until both inbound and outbound accuracy exceeded 85%. Inset is graphical representation of days to 85% accuracy in outbound performance (red). E, Graphical representation of animals' speed (purple) overlaid with arm choice (center arm, pink; right arm, blue; and left arm, green) across 5-min period of animal with >85% outbound accuracy (top). Example trace (bottom, left) in center arm, pink; right arm, blue; and left arm, green and heatmap (bottom, right) of animal with >85% outbound accuracy during 1-day behavioral test. Error bars indicate SEM.