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Background and Objective: Memory is an especial ability of brain in which saves the information and reuptake it. The memory is depended on hippocampus and amigdal. The neuronal density of hippocampus and amigdal have direct effect on their physiological functions. Cannabis sativa is belongs to Cannabinaceae family that Tetrahidrocanabinol is important component of this plant. The aim of this study was to assess the effect of alcoholic extract of Cannabis sativa on CA1, CA2 and CA3 subfeilds of hippocampus neuronal density in male Rats.

Materials and Methods: This experimental study was performed on 18 male Rats with (250-320gr) weight and 3 month old in faculty of science, Islamic Azad University of Mashhad, Iran (2010-2011). At first the alcoholic extraction was provided by the soxhlet method of the seed of this plant with coded 2548. Eighteen male wistar Rats were allocated into 2 experimental groups (25,75mg/kg of alcoholic extract of Cannabis sativa) and one control group. Alcoholic extract of Cannabis sativa was injected intraperitonealy (I.P.) in experimental groups for two weeks (every week one injection). After four weeks animal was decapitated and their brain dissected, fixed in 10% formalin, sectioned in 7μm thickness and stained by toluidin blue. By applying stereological techniques and systematic random sampling scheme the neuronal density of hippocampus were estimated.

Results: Neuronal density in control and treated with alcoholic extract (25,75mgkg) CA1 was 17982, 26750 and 22801 respectively. Neuronal density in CA2 was 19171, 26750 and 22801 respectively and also in CA3 was 19391, 24043, 28571 respectively. Neuronal density in CA1, CA2 and CA3 of hippocampus in treated groups with alcoholic extract (25,75mgkg) was significantly increased in comparision with controls (P<0.01).

Conclusion: This study determined that the alcoholic extract of Cannabis sativa can induce hippocampus neurogenesis which is not dose depended.

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Background and Objective: After axotomy or the compersion the nerve, the death of spinal cord nerves cell body occur. Compersion is one of the factors causing the degeneration of the spinal cord cell body. This degeneration is due to the reversed factors of the damaged area that have reached to cell body. Prosopis farcta is a member of leguminosae family and mimosaceae subfamily. The purpose of this study was to investigate the effect of ethanolic extract of pod prosopis farcta plant, on neuronal density of anterior horn following sciatic nerve compression in rat. Materials and Methods: This experimental study was performed on thirty male wistar rats with the age of about three months years and 300-350 gr weight. The animals were divided into five groups. A) control, B) compression, C) compression + treatment with 25 mg/kg ethanolic extract, D) compression + treatment with 50 mg/kg ethanolic extract and E: compression + treatment with 75 mg/kg ethanolic extract. After anesthetizing the rats, the muscle of thigh was splited and the sciatic nerve was kept under compersion, the muscle and skin were stitched subsequently. In the experimental groups the alchoholic extract of the prosopis farcta was injected to the rats with 25mg/kg, 50mg/kg, 75mg/kg dosage by the intrapritoneal way weekly. After 28 days of compresion, the rat, were put under the perfusion method and some samples were taken of their lumbar spinal cord and after tissue processes, 7 micron slide were provided of the samples serially. Slides were stained by toluidin blue, and some photos were taken and neuronal density of the alpha motoneurons alpha anterior horn of the spinal cord was calculated by the disector method. Data were analyzed using Minitab software, ANOVA and t- tests. Results: The neuronal density in the compression group (628±29.7) was decreased significantly in compare to the control group (1562±35.3) (P<0.05). The neuronal density in group C (1070±91), increased significantly in compare to the compression group (p<0.05). The neuronal density in group D (1117±62.8) and group E (1669±86.5) significantly increased in compare to the compression group (P<0.05). Conclusion: This study showed that alchoholic extract of the prosopis farcta has a neuroprotective effect following sciatic nerve compression in rats.