The Effect of Age and Area of the Brain on the Concentration of Metals in Aβ Plaques in Tg2576 Mice

Studies have shown increased amounts of essential trace metals, zinc, copper, and iron, in human brains afflicted with Alzheimer’s disease (AD) and brains of transgenic mouse models of AD. However, no reports have been published on the concentrations in the amyloid plaques of an AD mouse model or the change in trace metal deposition in amyloid-β plaques with age. This study examined the change in concentrations of trace metals that occur with increasing age in the amyloid-β plaques in the brains of Tg2576 mice, a murine model of Alzheimer’s disease. Microprobe synchrotron x-ray fluorescence (SXRF), a non-destructive technique that can measure all of the elements present in the tissue at one time was used in this study. Additionally, comparisons were also done on the concentrations of zinc, copper, and iron across the three ages in the cortical plaques. Finally, differences in the counts of zinc, copper, iron, potassium, and calcium between plaque tissue and non-plaque brain tissue were investigated. The results showed a significantly lower concentration of copper in the plaques of the cortex of the oldest age group, 22 months, compared to the youngest group of mice, 12 months. There was also an overall trend towards significantly more copper in the cortical plaques compared to the hippocampal plaques. Finally, multi-channel analyses (MCA) showed that there were significantly higher counts of zinc, copper, iron, and a strong trend toward higher counts of potassium in the plaque tissue compared to the nonplaque brain tissue in the 18 month age group.

Author

• Gideons, Erinn

• Trace metals
• Zinc
• Copper
• Iron
• Synchrotron x-ray
• Alzheimer's Disease

Identifier

hdl:1920/6029

OAI identifier oai:identifier

oai:MARS:1920/6029