The Effectsof Manganese On The Neurogenesisand The Preliminary Discussion On SVZ

Object:To research the effects of manganese on the neurogenesis and the preliminary discussion on SVZ by euroethology and immunohistochemical staining method. On the other hand, to explore the damage and the mechanism of manganese exposure on brain, wish to research a basic management for occupational manganese exposured and provide a way for intervention treatment.Methods:1. Animals and Groups:choose 48(SPF) healthy adult male mice, weight between 18g to 22g (provided by experimental animal center of guangxi medical university).1 week for mice to adapt before experiment. The 48 male mice were randomly divided into four groups by weight. Respectively, the control group (CG), low dose group (LDG), medium dose group (MDG), high dose group (HDG),12 for each group.2. Neuroethology Test:Respectively, all mice were separately experimented by kuangchang field test, YLS-10B wheel test, suspension rope test.3. Manganese exposured mice model:To product different dose of manganese exposed groups:low does manganese exposure group, middle dose manganese exposed group, high dose manganese exposed group, all mice were prepared by intraperitoneal injection with different concentrations of manganese chloride (MnCl·4H2O)solution. Respectively, three different dose 3.75 mg/kg,7.5 mg/kg and 15 mg/kg were solvented in saline solution. The control group mice were done by intraperitoneal injection with the same volume of physiological saline (0.9% Nacl solution). Every mice were injected once a day, canister to four consecutive weeks.4. Neuroethology test after manganese exposured:All group mice were tested by three sets of behavioral science experiment.In order to observe and detect the effects of different doses of MnCl2on the coordination of mice body movement. The mice behavior level can be used as evaluation of Mncl2 on the function of nervous system.5. Immunohistochemical staining results:To detect the expression of GFAP, DCX on the lateral ventricle of each group by using immunohistochemical method.Calculated on the number of positive cells by using immunohistochemical image、spss16.0 statistical software and GraphPad Prism 5 software.Result:1. Behavioral experiment:(1)Kuangchang field testThere were noobviously differences of the total movement distance between the four groups before manganese exposured and those mice were suitable for experiment. After manganese exposured, all group mice movement distances had a sum of differences among each other. Built after manganese injection, on the 1 d,2 d and 3 d, Compared with CG group, there had no significantly shortened of the total movement distance of LDG. There were no statistically significant differences between the two groups LDG and CG. While the total movement distance of the two groups MDG and HDG mice were significantly shortened than CG, and the differences was statistically significant (P< 0.05), as well as the total movement distance of two groups MDG and HDG mice were shorter thanthat in the LDG group, while there were no statistically significantly differences between MDG and HDG (P> 0.05). (2)Suspension test results: There had no obvious differences of suspension time between the four groups CG, LDG, MDG and HDG before manganese exposured. Before building, the suspension time on the suspension rope among the four groups mice and there had no obvious differences among each other. On the 1 d, Compared with CG group, the suspension time on the suspension rope the three groups mice LDG、 MDG and HDG did not had significantly shorter. While there were no statistical significances on the time of three groups mice (P>0.05). On the 2 d and 3 d, the suspension time of three groups of mice LDG、 MDG and HDG were significantly shortened than group CG, which had statistically significances meaning (P< 0.001). The time of the two groups MDG and HDG had obviously shorten group LDG, which exist statistically significant differences (P< 0.05), while there were no significantly differences of the time on the test between the two groups MDG and HDG, those mice had not obviously shortened between each other (P> 0.05). (3)YLS-10B wheel test results:The stay time in the first day on the wheel and the wheel rotational distance of LDG, MDG and HDG groups with manganese exposure had no obvious differences than CG, and had no significantly differences between three groups LDG, MDG and HDG. In the second day, there were no significant differences of the distance on the wheel rotational among the four groups CG, LDG, MDG and HDG. The duration time of the two groups MDG and HDG on the wheel had significantly shorter than the group CG (P<0.05). The residence time of MDG and HDG in the runner have obviously shorter than LDG (P< 0.05). There were no significant differences between the two groups MDG and HDG. On the third day, the staying time on the wheel rotation between the two groups MDGand HDG, and there had significantly shorten than CG (P< 0.05). And the retention time and the rotation distance of two groups MDG and HDG were significantly shortened than LDG (P< 0.05).While there had no obvious differences between two groups MDG and HDG of residence time and rotational distance. On the last day, the stay time in the wheel of the two groups MDG and HDG had significantly shorten than CG (P< 0.05), and the rotation distance of HDG on wheel had obviously shortened than CG (P<0.05). The sidence time on the wheel of HDG were significantly shorter than LDG (P< 0.05), while the distance on wheel turns among the three groups LDG、HDG and MDG had obviously shorten than CG (P<0.05), there were no significant differences between the two groups LDG and MDG (P>0.05).2. Immunohistochemical results:(1) GFAP immunohistochemical results: The positive cells number of GFAP in the SVZ area in the two groups of MMG and HMG had significantly increased than CG (P< 0.001).There were no obviously differences between the two groups LDG and CG, as well as the two groups MDG and HDG. (2) DCX immunohistochemical results:The positive expression cells number of DCX in the SVZ in two groups MDG and HDG had significantly decreased than CG (P< 0.001). While there were no significantly differences between the two groups LDG and CG, as well as there had no obviously differences between MDG and HDG.Conclusion:1. Manganese exposured can damage the function of brain on extrapyramidal, resulting in a decline in exercise capacity.2. Manganese exposured can inhibit the neurogenesis in the SVZ, and reduce the formation number of new neurons.3. Manganese exposure could product a negative effects on the function of SVZ, the mechanism of manganese exposured which it could inhibitthe neurogenesis in the SVZ.4. The mechanism of Manganese poisoning might be related to the result of neurogenesis inhibition in the SVZ.