:: Volume 17, Issue 4 (Iranian South Medical Journal 2014) ::
Iran South Med J 2014, 17(4): 524-532 Back to browse issues page
The effects of intrahippocampus injection of progesterone on passive avoidance learning and memory in adult male rats
Tahmoores Shahrivar1, Ahmed Ali Moazedi2, Abdul Rahman Rasekh2, Sahar Almasi-Turk3, Amrullah Roozbehi 4
1- Cellular and Molecular Research Center, School of Medicine, Yasouj University of Medical Sciences, Yasouj, IRAN
2- Department of Biology, School of Science, Shahid Chamran University, Ahwaz, IRAN
3- Department of Anatomical Sciences, School of Medicine, Boushehr University of medical Sciences, Boushehr, IRAN
4- Cellular and Molecular Research Center, School of Medicine, Yasouj University of Medical Sciences, Yasouj, IRAN , aroozbehi@yahoo.com
Abstract:   (4167 Views)

Background: Progesterone as a reproductive hormone is studied in the brain structure. New studies are mainly about systemic injection and have shown that the progesterone has different effects on memory. But it is not clear if hippocampus is mediator of progesterone in reinforcement of memory and learning. So, the effects of intra-hippocampal injection of progesterone on passive avoidance memory and learning was studied in male Wistar rats. Material and Methods: Animals were divided in eightgroups as a control, saline, almond oil (as a vehicle) and progesterone groups (0.5, 1, 1.5, 2, 3µg/Kg. body weight). All groups except the control were cannulated in left CA1 area by stereotaxic device. One week after recovery, all groups were trained by shuttle box and immediately after training different doses of progesterone in the volume of 0.5μL were injected through the cannula in CA1 of hippocampus and control groups received saline and almond oil at the same volume and condition respectively. After 48 hours passive avoidance memory and learning was evaluated. Results: Statistical analysis showed that 0.5, 1.5, 2 µg/µl progesterone groups had significantly improved passive avoidance learning and memory compared with saline group (p <0.001), but 1 and 3 µg/µl progesterone groups did not show significant effect on passive avoidance learning and memory compared with saline group. Also almond oil increased passive avoidance learning and memory compared with saline group (p <0.001). Conclusion: It seems that effects of progesterone as a neurosteroid on memory and learning depend on its dose. Also almond oil contains vitamin E, omega 3 and oleic acid that has beneficial effects on learning and memory.

Keywords: learning, memory, progesterone, hippocampus, shuttle box
Full-Text [PDF 717 kb]   (1485 Downloads)    
Type of Study: Original | Subject: General
Received: 2014/08/11 | Accepted: 2014/08/11 | Published: 2014/08/11


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Volume 17, Issue 4 (Iranian South Medical Journal 2014) Back to browse issues page