The comparison of neurobehavioral changes and impaired locations between the mouse model of manganism and Parkinson's disease

Abstract

Objective: To investigate the effect of manganese chloride (MnCl(2)) or 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) on the neurobehavioral and histopathology in C57BL/6 mice and provide evidence for the diagnosis, treatment and prevention of manganism. Methods: Adult male C57BL/6 mice were treated with MnCl(2) and MPTP respectively by intraperitoneal injection at the doses of 5, 10, 20mg Mn/kg and 30mg MPTP/kg. Controls were injected equivalent normal saline. All animals were administrated 5 times a week for 4 consecutive weeks and sacrificed after behavior tests on the fifth week. Balance ability, anxiety and depression level and cognitive function were tested respectively by vertical pole test, open field locomotion test and Morris swim task. The neuron pathological changes of striatum and substantia nigra were examined through HE-staining pathological section by using optical microscope. Results: Compared with the control group, the high dose of MnCl(2) reduced body weight obviously (P<0.01) . The results of vertical pole test showed that MnCl(2) and MPTP lengthened the pole-climbing time and turnaround time. Open field locomotion test showed that movement distance, stand-up time and central field time were decreased after the exposure of MnCl(2) or MPTP. In the Morris swim task, the escape latency time increased and the target quadrant activity time decreased significantly after the injection of MPTP as well as high-dose MnCl(2), comparing with controls (P<0.05) . Moreover, the escape latency time of high dose MnCl(2) prolonged prominently comparing with MPTP grou (P<0.05) . The results of histopathology showed that acidophilic changes elevated in MnCl(2) and MPTP group, comparing with controls. Furthermore, in striatum the oxyphil cells number increased in MnCl(2) high-dose group comparing with MPTP group (P<0.01) . On the contrary, there were more oxyphil cells in MPTP group comparing with MnCl(2) groups in substantia nigra (P<0.01) . Conclusion: Both manganese and MPTP can induce the impairment of dopaminergic neural system, but the symptons and injured location of manganism are inconsistent with PD models induced by MPTP.