chronic treatment by l-name differently affects morris water maze tasks in ovariectomized and naïve female rats

introduction: the role of ovarian hormones and nitric oxide (no) in learning and memory and their interaction has been widely investigated. the present study carried out to evaluate different effect of l-name on spatial learning and memory of ovariectomized (ovx) and sham operated rats. methods: 32 rats were divided into 4 groups: 1) sham 2) ovx 3) sham-ln and 4) ovx-ln. the animals of groups 3 and 4 were treated by l-name (10 mg/kg/ day) for 8 weeks while the animals of groups 1 and 2 received saline (1ml/kg/day) instead of l-name. the animals of all groups were then tested in morris water maze during five days. the escape latency and traveled distance were compared between groups. results: distance and time in ovx group was significantly higher than sham group (p<0.01 and p<0.05). time and distance in sham-ln group was higher in comparison with sham group (p<0.05 and p<0.01). there were no significant differences between ovx-ln and ovx groups in escape latency and traveled distance. discussion: the results of present study showed that removal of ovarian hormones could impair morris water maze tskas includiong time and distance. administarion of non specific nitricoxide inhibitor, l-name, affects morrsi water maze tasks however, its effect is different in the absence and presence of ovarian hormones but it needs to be more investigated.