Memory function often declines with age1, and is believed to deteriorate initially because of changes in synaptic function rather than loss of neurons2. Some individuals then go on to develop Alzheimer's disease with neurodegeneration. Here we use Tg2576 mice, which express a human amyloid-β precursor protein (APP) variant linked to Alzheimer's disease, to investigate the cause of memory decline in the absence of neurodegeneration or amyloid-β protein amyloidosis. Young Tg2576 mice (< 6 months old) have normal memory and lack neuropathology, middle-aged mice (6–14 months old) develop memory deficits without neuronal loss, and old mice (> 14 months old) form abundant neuritic plaques containing amyloid-β (refs 3–6). We found that memory deficits in middle-aged Tg2576 mice are caused by the extracellular accumulation of a 56-kDa soluble amyloid-β assembly, which we term Aβ*56 (Aβ star 56). Aβ*56 purified from the brains of impaired Tg2576 mice disrupts memory when administered to young rats. We propose that Aβ*56 impairs memory independently of plaques or neuronal loss, and may contribute to cognitive deficits associated with Alzheimer's disease.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
We thank S. Younkin, D. Walsh, M. Podlisny, D. Selkoe, J. Cleary and S. Prusiner for critical discussions. We are grateful to D. Cooper-Blacketer, J. McQuail and M. Sherman for technical help, and A. Delacourte and N. Sergeant for providing the APPC17-Cter antiserum. This work was supported by grants from the NIH (to K.H.A., M.G. and A.Y.) and a gift from M. and H. Hobbs to M.G. Author Contributions S.L. and K.H.A. conceived the project. S.L. planned, performed and analysed the biochemistry experiments, including the protein extractions and purification of Aβ*56. K.H.A. wrote most of the paper. M.T.K. and M.G. planned, performed and analysed the rat behavioural experiments, and L.K. planned and analysed the mouse behavioural experiments. A.Y. provided the mass spectrometry analysis of purified Aβ*56, C.G.G. provided biochemistry advice, and C.G.G. and R.K. donated the A11 antiserum.
This file contains the Supplementary Methods, Supplementary Discussion (on the selective effects of Aβ*56 on retention, but not acquisition of spatial memory) Supplementary Table 1, Supplementary Figures 1–7 and additional references.
About this article
Nature Reviews Molecular Cell Biology (2018)