Rats were trained to swim to hidden platform in the water maze (Morris, 1984). The maze consisted of a 120 cm diameter, 46 cm high circular pool filled with black ink and maintained at 25–26°C. The 10 cm diameter platform was 0.5–1 cm below the surface of the black ink water. The pool was placed in the center of an enclosure with white walls and a colored geometric figure on each of the walls (triangle, square, circle, and strip) that served as spatial cues. In the place navigation task which included 3 consecutive days, each rats was placed in the pool six times, starting in a random order of direction: north, south, east, or west with 30-min intervals between trials. In each trial, rats were placed in the pool facing the wall in one of four
