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Background & Objective: The pattern of cell types in vertebrate embryos depend on the function of organizing centers, specialized cell groups that direct the fate of nearby cells through the secretion of inductive factors. Our previous studies showed that during early neural tube formation, the notochord is essential for the induction of ectoderm and for the subsequent differentiations of the neuroepithelium. It is well known that glycoconjugates are developmentally regulated expression on the surfaces of early embryonic cells and could therefore be involved in many critical morphogenetic and histogenetic events during embryonic development. Materials & Methods: In the present study, histochemical studies were carried out to detect the presence and distribution of terminal sugars during development of precursors of motor neurons within the developing spinal cord in balb/c mice. Embryos from day 9 to 14 of gestation were fixed and processed for lectin histochemical studies by using horseradish peroxidase labeled WFA with binding specificity for terminal N-acetylgalactosamine. Results: The first reaction was occurred weakly on the cells surface and extra cellular matrix just around the peripheral portion of floor plate on day 13 of gestation. It seems that these cells are developing premotor neurons, which will form the future motor neurons of the spinal cord. The reaction increased significantly and extended to the deep part of spinal floor plate by day 14. Conclusion: These data indicate that glycoconjugates containing N-acetylgalactosamine may play important roles in differentiation of the floor plate motor neuron and perhaps glia cells in final development of the ventral part of the spinal cord.

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Background and Objective: Neurons are injured under physical, chemical and pathological conditions. The effects of injuries in peripheral nervous system returns as retrograde to the cell body of neurons in central nervous system and causes brain and spinal degeneration. This study was done to evaluate the effect of aquatic extract of Cannabis sativa leaves on degeneration of alpha motoneurons in spinal cord after sciatic nerve compression in Rats.

Materials and Methods: This experimental study was carried out on thirty two male Wistar rats, weighing 300-350 grams. Animals were divided into four groups each consisting eight members A: control, B: compression, C: compression + treatment with 25 mg/kg aquatic extract, D: compression + treatment with 50 mg/kg aquatic extract. In order to induce compression in B, C and D, after cutting the right thigh muscle, Sciatic nerve of thigh was exposed to compression for 60 seconds using locker pincers. The first extract injection was done intraperitoneally immediately after compression and the second intera peritoneal injection was done 7 days later. 28 days after compression, the Lumbar spinal cord were dissected, fixed and stained with toluidine blue. The density of alpha motoneurons was measured using dissector and stereological methods. Data was analyzed with using Minitab-13 software, ANOVA and Tukey tests.

Results: Neuronal density was 611.5±34.2 and 1633.4±30.7 in compression and control groups respectively (P<0.001). There was a meaningful statistical increase in neuronal density of group C (1278.6±28.1) in comparing compression group (P<0.001). The neuronal density in group (D) (1549.8±87.7), significantly increased in comparison with group (B) (P<0.001).

Conclusion: This study showed that aquatic extract of Cannabis sativa leaves increases the density of alpha motoneurons in spinal cord after sciatic nerve compression in Rats. The increase in neuronal density is relevant to the amount of extract used.

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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.

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Background and Objective: Compression or sciatic axotomy induces neuronal death in spinal cord alpha motor neuron. This study was carried out to determine the effect of Nigella sativa seed alcoholic extract on spinal motor neuron density in anterior horn after sciatic nerve compression in rat. Materials and Methods: In this experimental study 24 wistar rats were divided into four groups A: control, B: compression, C: compression+treatment with 75 mg/kg alcoholic extract, D: compression+treatment with 50 mg/kg alcoholic extract. In control group muscle was exposed without any injury to sciatic nerve. In compression and treatment group, the right leg sciatic nerve compressed for 60 sec. After four weeks of post operation, L2-L4 and S1, S2 and S3 segments of spinal cord were sampled, processed, serially sectioned and stained with toluidine blue. The number of alpha motor neurons was counted using dissector method. Results: Neuronal density in compression group (650±32) significantly decreased in comparison with control group (1803±24). Neuronal density in C treated group (1581±47) and D treated group (1543±49) significantly increased compare to compression group (P<0.001). Conclusion: Alcoholic extract of Nigella sativa seed increased the density of alpha motor neurons in spinal cord after sciatic nerve compression in rats.

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Background and Objective: Previous studies have shown the adverse effects of gestational diabetes on hippocampal neuron density in animal model. This study was conducted to determine the effect of gestational diabetes on number of motor neuron in the ventral horns of spinal cord in 4, 8 and 12 weeks rat offspring. Materials and Methods: In this experimental study, 30 Wistar dams were randomly allocated in control and diabetic groups. Dams in diabetic group were received 40 mg/kg/bw of streptozotocin (STZ) at the first day of gestational day (GD) and control group were received an equivalent volume normal saline, intraperitoneally. Six offspring of cases and controls were randomly selected at the 4, 8, 12 postnatal weeks. Postnatal rats were scarified and sections (6 micrometer) were taken from the cervical part of spinal cord, stained by cresyl violet. A photograph of sections was produced using an Olympus BX51 microscope and a DP12 digital camera. The number of motor neurons in the right ventral horns of spinal cord was evaluated in 100000 μm2 area of spinal cord using OLYSIA Autobioreport software. Results: The number of motor neurons in 4 weeks rat offspring were reduced (24.90%) in gestational diabetics compared to controls (17.16±0.5 vs22.85±2.1, P<0.05). The motor neurons in 8 weeks rat offspring were reduced (32.95%) in gestational diabetics in comparison with controls (17.70±1.7 vs26.40±2.0, P<0.05). Also, the number of motor neurons in 12 weeks rat offspring were reduced (24.38%) in gestational diabetics in comparison with controls (17.83±0.7 vs23.58±1.4, P<0.05). Conclusion: The uncontrolled gestational diabetes reduces the number of motor neurons in the ventral horn of spinal cord in rat offspring.

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Background and Objective: Monosodium glutamate (MSG) is used as a food additive. Several studies have reported the adverse effects of Monosodium glutamate on the testis and brain. This study was performed to determine the effect of Monosodium glutamate in rat cerebellum. Methods: In this experimental study, 24 adult wistar rats randomly allocated into three groups including experiment A, experiment B and control (C). The animals in experiment A and B were received 3g and 6g of MSG thoroughly mixed with their feeds for 14 days, respectively. Animals in control group were received MSG free diet. Food and water for rats to be free in all of experimental time. The rats were sacrificed on fifteen day. The cerebellum dissected and fixed with formalin 10% buffer and stained with hematoxylin and eosin. Results: Disorders and detachment were observed in Purkinje and granular cell layers. Neural cell distribution in granular layer redeuced in the experimental groups. Cellular degenerative changes in the granular layer of the experimental B were more severe than experimental group A. The mean number of neuron of the granular layer in the experimental A, B and control groups were 2750, 2140 and 3150, respectively. Conclusion: The consumption of monosodium glutamate dose dependly causes histopathological changes and reduces the number of the cerebellumllar neurons in adult rat.

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Background and Objective: Parkinson disease (PD) is the second most common neurologic disorder that results following degeneration of dopaminergic neurons in the pars compacta of substintia nigra (SNc). The 1-methyl-1,2,3,6-tetrahydropiridine (MPTP) is a chemical neurotoxin that widely used in animal models of PD. This study was carried out to evaluate the numerical density of dark neurons (DNs) in the SNc in mice subjected to intraperitoneal and intranasal injection of different doses of MPTP. Methods: In this experimental study, 90 male adult BALB/c mice were randomly allocated into four experimental groups including: group 1 (MPTP was injected via i.p. at the dose of 20mg/kg per 2 hours for 4 times), group 2 (MPTP was injected via i.p. at the dose of 30mg/kg for 5 consecutive days), group 3 (MPTP was injected via i.n. at a single dose of 1mg/kg), group 4 (MPTP was injected via i.n. at a single dose of 1mg/kg), four sham and one normal groups. 20 days after the final injection, the animal's brain were removed and stained by toluidine blue. Numerical density of DNs was counted. Results: Intranasal injection of MPTP significantly increased density of dark neurons in the pars compacta of substintia nigra in compare to intraperitoneally injection of MPTP (P<0.05). Conclusion: Intranasal injection of MPTP is more effective manner to induce degeneration of neurons in substintia nigra in animal model of Parkinson's disease.

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Background and Objective: Hippocampus is the main region in cortex of the brain that involved in epilepsy. This study was done to determine the effect of intraventricular injection of vitamin C on histological structure of dentate gyrus of hipocampus in adult male epileptic rats.

Methods: In this experimental study, 40 adult male rats were randomly allocated into 5 groups (n=8). Animals in three groups were received vitamin C at dose (12.5, 25 and 50 mg/kg/bw) during 28 days, intraventricularly after were kindled by (pentylentetrazol; 40 mg/kg). Animals in forth group were received normal saline after were kindled by (pentylentetrazol; 40 mg/kg). Animals in the fifth group were received normal saline. After 28 days, rats were anesthetized by ketamin, then structure of hypocamp dissected. Histological passage was done in samples and coronal section was carried out. The sections of samples were stained by Hematoxyline-eosin. Forty fields systematicly were counted the normal neurons in dentate gyrus. Morphological change was determined by immunohistochemical method.

Results: The mean  number of normal neurons in dentate gyrus in epileptic rats which  received 25 g/kg vitamin C was more than animals in groups which were received doses of 12.5, 25 and 50 mg/kg vitamin C (P<0.05). This mean number of normal neurons in dentate gyrus of hypocamp in epileptic rats which received normal saline was lower than control and other experimental groups (P<0.05). Extensive morphological change in neurons of dentate gyrus in epileptic rats which received normal saline were observed (P<0.05). The lowest  morphological change were observed in neurons of dentate gyrus in epileptic rats which received at dose 25 mg/kg vitamin C in compared to the other groups (P<0.05).

Conclusion: Intraventricular injection of vitamin C in epileptic rat's dose dependly had neuroprotective effect on dentate gyrus neurons.

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Background and Objective: Transaction or laceration and compression of peripheral nerves in accidents and different circumstances resulting Wallerian degeneration which go back to perikaryon through retrograde reaction. This study was done to determine the effect of alchohlic extract of Achillea wilhelmsii on density of motor neurons of spinal cord after sciatic nerve compression in male Wistar rats.

Methods: In this experimental study, 30 male wistar rats were randomly allocated into 5 groups: group A: control, group B: compression, group C: compression and treatment with 50 mg/kg/bw of ethanolic extract, group D: compression and treatment with 75 mg/kg/bw of ethanolic extract and group E: compression and treatment with 100 mg/kg/bw of ethanolic extract of Achillea wilhelmsii. After anesthetizing rats, skin and sub cutaneous muscles of right thigh were cut to sciatic nerve appears. Then, compression of sciatic nerve was done by a surgical forceps for 60 seconds, followed by suturing muscle and skin. Extract injection was done intraperitoneally for three weeks after compression. Group A and B were received normal saline. 28 days after compression, samples were prepared from lumbar spinal cord under perfusion method and histological sections were provided serially. After staining, density of motor neurons was calculated by dissector method.

Results: Neuronal density in the compression group (707±38.56) significantly reduced in compare to control group (1740±49.81), (P<0.05). Neuronal density in group C (1208±57.58), group D (1370±33.91), and group E (1437±64.46) significantly increased in compare to compression group (P<0.05), respectively.

Conclusion: Ethanolic extract of Achillea wilhelmsii increased neuronal density of rat's spinal cord after compression of sciatic nerve.

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Background and Objective: The degeneration of motor neuron in anterior horn of spinal cord can be caused by compression. Hyssopus officinalis of Laminacea family demonstrate antioxidant and anti-inflammation effects. This study was done to evaluate the effect of alcoholic extract of Hyssopus officinalis leaves, on motor neuron in spinal cord after sciatic nerve compression in male rats.

Methods: In this experimental research, 60 male wistar rats were randomly allocated into six groups including; control, compression, and compression + treatment (25, 50, 75, 100 mg/kg/bw). In order to induce compression, sciatic nerve of right leg was exposed to compression for 60 second using locker pincers. Extract injected intraperitoneally in the first and second week after compression. 28 days after compression under profusion method, the lumber spinal cord was sampled. The density of motor neurons (9-20 micron) was measured using dissector and stereological method.

Results: Density of neurons in compression group (611±34) significantly reduced compared to the control group (1658±30) (P<0.05). Moreover, neuronal density was significantly increased in
25 (1179±22), 50 (1260±20), 75 (1350±15) and 100 (1120±10) mg/kg/bw doses in treatment groups in compared to the compression group (P<0.05).

Conclusion: Alcoholic extract of Hyssopus officinalis leaves exhibite neuroprotective effect on neurons in anterior horn of the spinal cord after injury. This effect probably is related to the antioxidant and anti inflammation properties in alcoholic extract of Hyssopus officinalis, dose dependly.

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Background and Objective: Brain is not able to produce new neurons by neurogenesis after maturity. Neurogenesis after the maturity was reported in Hippocampus and subventricular areas in the brain. Rosa canina L has various vitamins and other valuable compounds such as polyphenols, carotenoid, carbohydrates and fatty acids. This study was conducted to evaluate the effect of the alcoholic extract of the fruit of Rosa canina L plant on neuronal density of the hippocampus in animal model.
Methods: In this experimental study 24 adult male mice were randomly allocated into 4 groups including: control and three treatent groups. Animals in treatment groups 1, 2 and 3 were received the alcoholic extract with extract with a dose of 25, 50, 75 mg/kg/bw intraperitoneally (IP), for 21 day continuously with an invertal of 24 hours, respectively. Animals in control group were received normal saline injection. One month after the first injection, the animals were anesthetized and brain gently was out of the skull. After processing, seven-micron serial sections were stained with blue toluidine and erythrosine. Different regions of the hippocampus were photographed and neuronal density was evaluated by stereological methods and was compared with control group.
Results: The mean neuronal density of CA1 area of hippocampus in control and the treated group with a dose of 25, 50, 75 mg/kg/bw was 55±2, 70±3, 65±3 and 61±2, respectively. Neuronal density significantly increased in treatment group with dosage of 25 mg/kg/bw in compared to control group (P<0.05). The mean neuronal density of CA2 and CA3 area of hippocampus in treated group with a dose of 25, 50, 75 mg/kg/bw was not significant in compared to controls.
Conclusion: This study showed that the alcoholic extract of the fruit of Rosa canina L plant with dosage of 25 mg/kg/bw increase neurons of the mice hippocampus.