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Background and Objective: Ischemia-reperfusion invoke cell death in hippocampus. This study was carried out to investigate the effect of transforming growth factor alpha (TGF-alpha) of dentyte jyrus neurons and pyramidal cells of CA1 subfiled of hippocampus following ischemia-reperfusion in rat models. Materials and Methods: This experimental study was done on 40 male Wistar rats weighing 250-300gr. Animals were divided in four groups: control (n=7), sham (n=7), ischemia (n=14) and treatment (n=14). Sham group was just under surgical stress. In ischemia and treatment groups after induction of ischemia-reperfiusion by obstruction of carotid arteries blocked for 30 minutes, reperfusion PBS (phosphate buffer salin) and subsequently TGF-alpha (50 ng) were injected stereotaxicaly in lateral ventricle, respectively. In 12 and 72 days after treatment the brains were fixated by transcardial perfusion and stained by immunohistochemestry and nissle methods. Furthermore, morris water maze was used to evaluate the learning memory. Data were analyzed using SPSS-16 and ANOVA test. Results: Injection of TGF-alpha increased the cell number in hippocampus of treatment group compared to ischemic group. TGF-alpha increased expression of neuron in dentyte jyrus of treatment group in comparison with ischemic group (P<0.05). Also spatial memory improved in treatment group in comparison with ischemia group. Conclusion: TGF-alpha improves ischemia-induced neurodegenration and memory impairment.

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Background and Objective: Considering the role of the hippocampus in memory, this study was done to evaluate the effect of 3-4,methylenedioxymethamphetamine on CA1 hippocampal neurons in male rats. Materials and Methods: In this experimental study 18 sprague dawley male rats (200-250g) were randomly allocated into three groups as follow: control (intact), control sham and experimental groups. Sham and experimental groups were received normal salin (1 cc) and MDMA10mg/kg IP for 7 days, respectively. Following transcardial perfusion by paraformaldehid 4%, structure and ultrastructure of right CA1 hippocampus were assessed by crysel violet staining and electronic microscope. Data were analyzed using SPSS-16, ANOVA and Tukey tests. Results: There was no significant difference between control (mean=210±40.38) and sham groups (mean=199±38.7) in neuron density. Neuron number decreased significantly in experimental group (mean=98±25.4) in compare to control and sham groups (P<0.001). There was no ultrastructural abnormality in control and sham groups. Finally, ultrastructural changes with apoptosis characterized by mitochondrial cristae reduction, distribution of nuclear chromatin and loss of cytoplasmic organelles in MDMA groups. Conclusion: This study shows that MDMA administration can stimulate the cell death with apoptotic pattern in hippocampus.