ABSTRACT
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
ABSTRACT
Several supra spinal areas such as rostral ventrolateral medulla [RVLM] area are involved in basic cardiovascular regulation. The Kolliker- Fuse nucleus [KF] is located in pons and is heavily connected with RVLM. The cardiovascular effect of KF nucleus has been shown and it is suggested that KF is involved in sympathetic vasomotor tone and basic cardiovascular regulation. Therefore, in the present study, the effects of KF on basic cardiovascular values were evaluated. After induction of anesthesia, a polyethylene catheter [PE-50] filled with heparinized saline was inserted into the femoral artery of rats. Animals were then placed in a stereotaxic apparatus and KF nucleus was inactivated by microinjection of cobalt chloride [CoCl2]. Blood pressure and heart rate [HR] were continuously recorded pre and post inactivation. Our result showed that inactivation of KF slightly changed mean arterial blood pressure [MAP] [92.3 +/- 2.45 mmHg vs. 90.86 +/- 1.7 mmHg] and HR [343.8 +/- 4.6 beats/min vs. 350.7 +/- 8.32 beats /min]. However, these effects were not significant in comparison to the control group. We concluded that synapses in the KF nucleus have no effect on regulation of basal blood pressure and heart rate, because CoCl2 is a synaptic blocker