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Background and Objective: Post-traumatic stress disorder (PTSD) impairs spatial learning and memory. Desmopressin acetate ameliorates the cognitive deficits induced by electroconvulsive shock. This study was designed to evaluate the protective effects of Desmopressin acetate on retention of spatial memory deficits induced by post-traumatic stress disorder in rats. Materials and Methods: In this experimental study twenty one male Wistar rats were used. Animals were trained for 5 consecutive days in Morris water maze and then were randomly assigned in three groups (Vehicle + Sham, Saline + PTSD and Desmopressin acetate + PTSD) and tested in a probe 60 sec in 24h after the last acquisition trial. The groups of PTSD+Desmopressin acetate rats and vehicle+sham, saline+PTSD were injected Desmopressin acetate (10 micro gr/kg body weight) and saline (IP), respectively. Injections performed ten minute prior to PTSD and spatial memory was tested ten minutes later. Data were analyzed using SPSS-16, One-Way ANOVA and Tukey tests. Results: The platform location latency of the Desmopressin acetate+PTSD group was significantly shorter (4.24 sec) than the control group (P<0.05) and also, had significantly smaller average proximity values (33.87 cm) compared to the saline+PTSD group (P<0.05). Desmopressin acetate + PTSD spent significantly more time (21.65%) in the target zone (P<0.05). Conclusion: This study indicated that Desmopressin acetate blocks the ability of PTSD to impair spatial memory retention.

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Background and Objective: Ducrosia anethifolia (Dc.) is a medicinal odor plant contains CNS effective compounds which has been used in Iranian traditional medicine. This study was done to determine the effect of Ducrosia anethifolia (Dc.) Boiss essential oil on spatial learning and memory in adult male rats.

Methods: In this experimental study, 35 wistar adult male rats were randomly allocated into the five groups (n=7) including: control, sham (injected vehicle) and Ducrosia anethifolia (Dc.) Boiss essential oil groups 0.125, 0.25 and 0.5ml/kg/bw, intraperitonally during four days. Morris water maze test was used to assess learning and memory.

Results: Ducrosia anethifolia (Dc.) Boiss essential oil (0.5 ml/kg/bw) was significantly increased escape latency in the second and third (P<0.05) as well as forth (P<0.05) days of acquisition test in compare to control group. In addition latency to find the hidden platform was significantly decreased with 0.25 essential oil in all days except first day (P<0.05) and in essential oil- treated rats at 0.125 ml/kg/bw in the second and third days (P<0.05) in compare to the control group.  Time spent and distance travelled in target zone were significantly increased in Ducrosia anethifolia (Dc.) Boiss essential oil -treated rats (0.5ml/kg/bw) in compare to control group (P<0.05).

Conclusion: Intraperental administration of the Ducrosia anethifolia (Dc.) Boiss essential oil at doses of 0.5 and 0.25 ml/kg/bw during four days can improves spatial learning and memory in adult male rats.

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Background and Objective: Atorvastatin is a member of the statin family with lipophilic character and anti-hyperlipidemic effect. There is many evidence that atorvastatin has protective effect on cognitive function. This study was done to evaluate the effect of atorvastatin on spatial memory in rats following a high-fat diet.
Methods: This experimental study was performed on 35 male Wistar male rats. Animals were randomly allocated into 5 groups including control, control plus atorvastatin and sham (received high-fat diet for 4 weeks) and high-fat diet plus atorvastatin (10 and 50 mg/kg, for 4 weeks). Learning and spatial memory were measured using Morris water maze for a 6-day period including 5 days training and the last day, test day (probe day).
Results: High-fat diet reduced learning and poor memory performance during training and probe compared to the control group, and also on the probe day, the high-fat group spent less time in the target quarter (P<0.05). Administration of atorvastatin after a high-fat diet improvement spatial memory in compared to high-fat group (P<0.05).
Conclusion: Short-term treatment (4 weeks) with atorvastatin in high-fat dietary rats can improve spatial memory.