ABSTRACT
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. 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 micro m sections of the brain stem were prepared, and hematoxylin and eosin [H and 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. 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. 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