First Author | Peneder TM | Year | 2011 |
Journal | Neuroscience | Volume | 180 |
Pages | 280-92 | PubMed ID | 21333719 |
Mgi Jnum | J:173693 | Mgi Id | MGI:5050022 |
Doi | 10.1016/j.neuroscience.2011.02.017 | Citation | Peneder TM, et al. (2011) Chronic exposure to manganese decreases striatal dopamine turnover in human alpha-synuclein transgenic mice. Neuroscience 180:280-92 |
abstractText | Interaction of genetic and environmental factors is likely involved in Parkinson's disease (PD). Mutations and multiplications of alpha-synuclein (alpha-syn) cause familial PD, and chronic manganese (Mn) exposure can produce an encephalopathy with signs of parkinsonism. We exposed male transgenic C57BL/6J mice expressing human alpha-syn or the A53T/A30P doubly mutated human alpha-syn under the tyrosine hydroxylase promoter and non-transgenic littermates to MnCl(2)-enriched (1%) or control food, starting at the age of 4 months. Locomotor activity was increased by Mn without significant effect of the transgenes. Mice were sacrificed at the age of 7 or 20 months. Striatal Mn was significantly increased about three-fold in those exposed to MnCl(2). The number of tyrosine hydroxylase positive substantia nigra compacta neurons was significantly reduced in 20 months old mice (-10%), but Mn or transgenes were ineffective (three-way ANOVA with the factors gene, Mn and age). In 7 months old mice, striatal homovanillic acid (HVA)/dopamine (DA) ratios and aspartate levels were significantly increased in control mice with human alpha-syn as compared to non-transgenic controls (+17 and +11%, respectively); after Mn exposure both parameters were significantly reduced (-16 and -13%, respectively) in human alpha-syn mice, but unchanged in non-transgenic animals and mice with mutated alpha-syn (two-way ANOVA with factors gene and Mn). None of the parameters were changed in the 20 months old mice. Single HVA/DA ratios and single aspartate levels significantly correlated across all treatment groups suggesting a causal relationship between the rate of striatal DA metabolism and aspartate release. In conclusion, under our experimental conditions, Mn and human alpha-syn, wild-type and doubly mutated, did not interact to induce PD-like neurodegenerative changes. However, Mn significantly and selectively interacted with human wild-type alpha-syn on indices of striatal DA neurotransmission, the neurotransmitter most relevant to PD. |