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Introduction & Objective: Effective materials from Valerian officinalis L. have too much usage in the pharmacological industry. It is used as a sedative, anticonvulsion, and antidepressant drug. Serotonin has a widespread role in vital function such as sleep, awareness and calmness. In this study we evaluated the effect of hydrochloric extract of valerian on number and size of raphe magnus neurons in adult rat. Materials & Methods: In this experimental study, which was conducted at Yasuj University of Medical Sciences in 2009, forty adult Wistar rats, each 170-250 gr, were divided randomly into four groups (one control group and three experimental groups). The animals were injected daily for one month with doses of 300, 400 and 600 mg/kg of the extract. The control group just received distilled water. After transcardial perfusion, the whole brain was separated, then 10 μm sections of the brain stem were prepared, and hematoxylin and eosin (H&E) staining were done. Number and size of raphe magna neurons were observed under light microscope. The gathered data were analyzed by the SPSS software using One-way ANOVA and LSD. Results: The control group did not statistically show significant changes in number of raphe magna neurons. Comparison of the means of long and short diameter neurons showed significant increases in experimental groups with control group (P<0.05). In experimental groups the neuron nucleuses were more euchromatic than the control group. Conclusion: Hydrochloric extract of valerian has no effect on raphe magnus neurons, but it is effective on neurons' size. It can be concluded that the extract increases both neurons activity and serotonin secretion.

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Introduction & aim: valerian root extraction is used in the treatment of sleep disorders, stress, depression, anxiety, muscle stiffness and tension. Astrocytes have role of nutrition, protection and support of the neurons. The purpose of this study was to investigate the effects of Valeriana extract on nucleus raphe magnus in the number and size of rat astrocytes. Methods: In the present experimental study, forty male Wistar rats weighing170-250g were randomly divided into four groups, including control and three experimental groups. The control group received distilled water and three experimental groups received 300, 400 and 600mg valerian root extract daily respectively for two weeks by gavage. Phsophotangestic acid staining was used to examine astrocytes. The size and number of astrocytes were calculated with LS.starter software. Data were analyzed, using SPSS software for statistical analysis and ANOVA and LSD tests. Results: The mean number of astrocytes in the experimental groups of three and four with the control group and experimental two showed a significant increase (P <0.05). Compare mean of great length of astrocytes in experimental groups of two, three and four with the control group showed a significant decrease and between the experimental group two and experimental groups of three and four a statistically significant differences were observed (P <0.05). Conclusion: Oral administration of hydro alcoholic extract of valerian increases astrocytes number and decreases their size in nucleus of raphe Magna, which indicated the effect of this extraction on proliferation of astrocytes increasing.