4.6. Cross Maze

Working memory was assessed by analyzing the spontaneous alternation behavior of mice in the cross maze [42,43]. The cross maze consists of four arms (30 cm length × 8 cm width × 15 cm height) arranged in a 90° position extending from a central region (8 cm length × 8 cm width × 15 cm height). During a single 10 min test session, each mouse was randomly placed in one arm, and allowed to freely explore the maze. Alternation was defined as successive entries into the four arms in overlapping quadruple sets (e.g., 1, 3, 2, 4 or 2, 3, 4, 1 but not 1, 2, 3, 1) [42]. The alternation percentage was calculated as the percentage of actual alternations to the possible number of arm entries. The ANY-Maze video tracking software (Stoelting Co, Wood Dale, IL, USA) was used to record the alternation rate, distance traveled, and speed. To diminish odor cues, the maze was cleaned with 70% ethanol solution between mice.