RESUMEN
In this research, the effects of treadmill running was studied on the passive avoidance learning and memory [PA] in matured male rats having been morphine dependent. In the behavioral stage, 36 rats weighing about 250g were housed in four groups as follows: Control; Morphine dependent; Exerciser and Exerciser's morphine dependent. Intraperitoneal injection [IP] of solved morphine with increased doses of, respectively; first three-day: 10mg/kg, second three-days 20mg/kg and third three-day, 40mg/kg were applied to make rats morphine-dependent. Treadmill running was performed in a ten-day period [two hours a day, at a speed of 12m/min and a incline of 15 degree] for the two groups of exerciser and exerciser's morphine dependent. Passive avoidance learning and memory test after attending physical exercises and making morphine- dependent were performed in similar conditions for all groups. On the basis of these results, in comparision to the average of the Control group with that of the Exerciser and Exerciser's morphine dependent groups; it is confirmed that physical activity strengthen the indicators of positive criterion [LS and Latency] and weaken the negative criterion [DS]. About the first indicator [Latency]: In the comparison of control group with the two groups of exerciser and exerciser's morphine dependent, a significant increase until 24 hours after footshock, and for the third indicator [LS] until one week after shock and for the second indicator [DS] a significant decrease until one week after shock was observed [***p<0.001, **p<0.01, *p<0.05]. In the meantime, no significant difference was observed for one month after shock [p>0.05].In comparison to control group with morphine-dependent group, except for the second indicator [DS] in which a negative criterion was considered, only a significant increase was observed 24 hours after footshock [p<0.05]. In comparison to the average of the second group [morphine-dependent] with the fourth group [exerciser's morphine-dependent], it was observed that there is a significant difference for Latency indicator until 24 hours after shock and for the indexicator of LS and DS until one week after footshock [+++p<0.001, ++p<0.01, +p0.05]. The result of behavioral steps showed that physical exercises increase the learning rate and strengthen short-term memory [STM] recalling, but it does not have any sensible effect on past event memory. Accordingly, it is said that probably some parts of hippocampus were influenced by physical activity. Moreover, physical exercise had treated the negative effects caused by morphine on the memory and learning in morphine-dependent rats, so that they recalled the past memories in the same way as the control group