Influence of Nano-Manganese Dioxide on Rat Spatial Learning and Memory Function and Its Injury for Rat Ventral Midbrain

摘要

Objective: To explore the influence of nano-manganese dioxide on the rat spatial learning and memory function and its injury for rat ventral midbrain. Methods: Under cerebral stereotaxis, the physiological saline was injected into the brains of rats in the control group, while nano-manganese dioxide was injected into the brains of rats in the experimental groups. Morris water maze tests were performed one, two, three and four weeks after the injection, respectively. The ventral brain tissues of rats in each group were separated, and RT-PCR and Western blot were used to detect the expression changes of tyrosine hydroxylase, glial fibrillary acidic protein and inducible nitric oxide synthase in the tissues. Results: Intracerebral injection of nano-manganese dioxide made the rats swim slower in Morris water maze test. Two and three weeks after the injection, the time of finding the platform for rats and the latent period became significantly longer. The search platform strategy changed from tendency type and stochastic type to tendency type and edge type. The analysis results of RT-PCR and Western blot showed that the tyrosine hydroxylase expression level in the rat ventral brain tissues decreased and the expression levels of glial fibrillary acidic protein and inducible nitric oxide synthase increased obviously (P < 0.05). Conclusion: Intracerebral injection of nano-manganese dioxide can affect the rat spatial learning and memory function, cause the destruction of dopaminergic neuron in the rat midbrain, the decrease of tyrosine hydroxylase expression level and the increase of the expression levels of glial fibrillary acidic protein and inducible nitric oxide synthase, and have certain injury for ventral midbrain.