Experimental animals and exercise
The Ethics Committee for Animal Experiments in the Isfahan University accepted the study plan.

Male Wister rats (n = 40) 90 ± 8 days old and weighing 350 ± 30 g from our laboratory breeding stock were housed singly under controlled conditions (temperature 20-24°, relative humidity 40-70%) and light/darkness cycle12/12 hrs (light on at 8:00 am). Food and water were available ad libitum. The measurements were always done during the first half of the light cycle. Rats were pre-tested for their treadmill running willingness, and those rats, which refused to run, were excluded before the experiments started. To minimize the stress, rats were familiarized to the treadmill running. Prior to Morris water maze test, rats in groups A, B, D were trained on the treadmill. All these animals tolerated the speed and duration of treadmill running and successfully completed the training program. The rats in group A participated in the treadmill exercise session (1 h at speed 17 m/min) for 30 days before and also during all the 8 days when Morris Water maze testing was carried out. Rats in group B participated in the treadmill exercise session (1 h at speed 17 m/min) just for 30 days before the Morris water maze test only. Rats in group D participated in the treadmill exercise session (1 h at speed 17 m/min) just during the 8 days only when Morris water maze testing took place. Rats in group C served as controls. For all groups, Morris water maze testing was performed in 8 consecutive days.

Behavioural apparatus
A black circular pool (150 cm diameter ×60 cm high) was filled to 30 cm deep with water (21°C) that was not opaque. A circular platform (10 cm diameter × 28 cm high) was placed within the pool, submerged approximately 2 cm below the surface of the water. The platform was placed in the center of a predetermined quadrant (North-East, North- West, South-East, and South-West) for each trial. The experimenters, computer and extra-maze cues remained constant throughout testing and lighting in the room was 30-50 Lux.

Morris water maze procedures
Each rat was handled daily, for 3 days before the experiments started. The water temperature in Morris water maze test is controlled during experiment (20-24°C). Before the training session rats were accustomed to the water maze for 30 s without a platform. Rat groups performed 4 trials on each of the 8 consecutive days and each trial began with the rat being placed in the pool and released facing the side wall at one of four positions (the Boundaries of the four quadrants, labeled N, S, E and W). Release positions were randomly predetermined, but the same for all rats on all trials for a given day of testing. The platform was placed in the center of a different quadrant each day (pseudo-randomly predetermined), but it remained in the same quadrant for four trials on a given day. On each trial, the rat was allowed to swim until it found and remained on the platform for 15 s, or until 90 s had passed and if it had not found the platform, at which point it was guided to the platform by the experimenter and allowed to stay on the platform for 15 s. Then the rat was removed from the pool, dried and placed back in its holding bin for a period of 5 min, after which the second trial was conducted. The time to reach the platform (latency) and the length of swim path were recorded semi- automatically by a video tracking system.

Data analyses
Data analyses were carried out by means of Analysis of Variance with groups and days as the independent variable, and performance in each session (path length and latency) as the dependent variable. All data were expressed as means ± SEM. The data of different groups was compared using Two-way ANOVA test with Tukey's Post-Hoc between days. Differences with p < 0.05 were considered significant.

Treadmill running for 30 days before and during the eight days of Morris water maze testing caused a significant enhancement of learning and memory in Morris water maze tests as the length of swim path was shorter in group A in comparison with control group C (Figure 1a and 1b). Same finding was made when the time i.e. latency was recorded (Figure 2a and 2b). In Morris water maze testing each group showed learning as both the swimming length and the time (latency) to find the platform shortened (Figure 1b and 2b). Rats of Group A found the platform in significantly shortest time in the Morris water maze in all testing days.

Group B of rats which had been exercising on the treadmill for 30 days before the Morris water maze tests but which did not continue the treadmill running sessions during the Morris water maze testing period lost some of the benefits obtained as the time to reach the platform., and their swimming pathway was statistically insignificantly different from the controls from the third day of testing in Morris water maze (Figure 1b).

The running exercises only during the 8 days of Morris water maze testing, .gave some benefit from the days six and onwards as then the path lengths were similar as in Group A and on the days seven and eight there seemed to be advantage over the controls participating only in the learning and memory testing (Figure 1b and Figure 2b).

Comparison within each group during the eight days of Morris maze testing, the path lengths revealed a significant progressive decrease in all groups except in controls whose path lengths stabilized after one week (p < 0.002) (Figure 1b) In this period, also the latency significantly decreased (p < 0.001) with again the exception of the controls whose latencies stabilized after one week (Figure 2b).