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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: Different organizers are involved in spinal cord development and differentiation by sending various messages. Specific glycoconjugates secreted from the cells of lateral wall of spinal cord can also act as neurogenesis and neural differentiation messengers. This study was carried out to determine the distribution of sugar compounds in the lateral walls of spinal cord during mice morphogenesis using lectin histochemistry method. Methods: In this experimental study, sections of BALB/c mice from 10-16 embryonic days were fixed in formalin and then histological sections were prepared. Tissue samples for reaction to the glycoconjugates were incubated with DBA, OFA, GSA1B4 and MPA lectins. Alcian blue with pH equal 2.5 was used for background staining. Results: DBA lectin did not react with the lateral wall of the spinal cord. MPA lectin showed severe reaction but consistent, especially in nerve fibers of the lateral wall of spinal cord. GSA1B4 lectin showed weak reaction in the cells and nerve fibers of the spinal cord, but severe reaction was clearly observed in blood vessels. OFA lectin showed severe reaction with α-L-Fucose terminal sugar in the lateral walls of the spinal cord in early stages of morphogenesis. Conclusion: The most reaction in the lateral walls of the spinal cord was related to OFA, which reflects the importance of fucose terminal sugar by connecting (1→6) to the penultimate sugar N-acetyl-D-glocosamin (Glc-Nac) in the development of spinal cord. Due to severe reaction of GSA1B4 to blood vessels of spinal cord, use of this lectin for vascular studies, is recommended.