Amyloid-β protofibril levels correlate with spatial learning in Arctic Alzheimer’s disease transgenic mice
Oligomeric assemblies of Amyloid-β (Aβ) are suggested to be central in the pathogenesis of Alzheimer’s disease, since levels of soluble Aβ much better correlate with the extent of cognitive dysfunctions than senile plaque counts do. Moreover, such Aβ species have been shown to be neurotoxic, to inte...
| Published in: | FEBS Journal |
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| Main Authors: | , , , , , , , , , , |
| Format: | Text |
| Language: | English |
| Published: |
2009
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| Subjects: | |
| Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2752010 http://www.ncbi.nlm.nih.gov/pubmed/19215301 https://doi.org/10.1111/j.1742-4658.2008.06836.x |
| Summary: | Oligomeric assemblies of Amyloid-β (Aβ) are suggested to be central in the pathogenesis of Alzheimer’s disease, since levels of soluble Aβ much better correlate with the extent of cognitive dysfunctions than senile plaque counts do. Moreover, such Aβ species have been shown to be neurotoxic, to interfere with learned behavior and to inhibit maintenance of hippocampal long term potentiation. The tg-ArcSwe model, transgenic mice with the Arctic and Swedish Alzheimer mutations, expresses elevated levels of Aβ protofibrils in the brain, making tg-ArcSwe a highly suitable model to investigate the pathogenic role of these Aβ assemblies. In the present study, we estimated Aβ protofibril levels in the brain and cerebrospinal fluid of tg-ArcSwe mice, and also assessed their role with respect to cognitive functions. Protofibril levels, specifically measured with a sandwich ELISA, were found to be elevated in young tg-ArcSwe mice, as compared to several transgenic models lacking the Arctic mutation. In aged tg-ArcSwe mice with considerable plaque deposition, Aβ protofibrils were approximately 50 percent higher than in younger mice, whereas levels of total Aβ were exponentially increased. Young tg-ArcSwe mice showed deficits in spatial learning and individual performance in Morris water maze correlated inversely with levels of Aβ protofibrils, but not with total Aβ levels. We conclude that Aβ protofibrils accumulate in an age-dependent manner in tg-ArcSwe mice, although to a far less extent than total Aβ. Our findings suggest that increased levels of Aβ protofibrils could result in spatial learning impairment. |
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