The Journal of Neuroscience, August 26, 2009, 29(34):10706-10714; doi:10.1523/JNEUROSCI.2637-09.2009
Previous Article | Next Article 
Neurobiology of Disease
Characterizing the Appearance and Growth of Amyloid Plaques in APP/PS1 Mice
Ping Yan, *
Adam W. Bero, *
John R. Cirrito,
Qingli Xiao,
Xiaoyan Hu,
Yan Wang,
Ernesto Gonzales,
David M. Holtzman, and
Jin-Moo Lee
Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri 63110
Correspondence should be addressed to Dr. Jin-Moo Lee, Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box: 8111, St. Louis, MO 63110. Email: leejm{at}neuro.wustl.edu
Amyloid plaques are primarily composed of extracellular aggregates of amyloid-β (Aβ) peptide and are a pathological signature of Alzheimer's disease. However, the factors that influence the dynamics of amyloid plaque formation and growth in vivo are largely unknown. Using serial intravital multiphoton microscopy through a thinned-skull cranial window in APP/PS1 transgenic mice, we found that amyloid plaques appear and grow over a period of weeks before reaching a mature size. Growth was more prominent early after initial plaque formation: plaques grew faster in 6-month-old compared with 10-month-old mice. Plaque growth rate was also size-related, as smaller plaques exhibited more rapid growth relative to larger plaques. Alterations in interstitial Aβ concentrations were associated with changes in plaque growth. Parallel studies using multiphoton microscopy and in vivo microdialysis revealed that pharmacological reduction of soluble extracellular Aβ by as little as 20–25% was associated with a dramatic decrease in plaque formation and growth. Furthermore, this small reduction in Aβ synthesis was sufficient to reduce amyloid plaque load in 6-month-old but not 10-month-old mice, suggesting that treatment early in disease pathogenesis may be more effective than later treatment. In contrast to thinned-skull windows, no significant plaque growth was observed under open-skull windows, which demonstrated extensive microglial and astrocytic activation. Together, these findings indicate that individual amyloid plaque growth in vivo occurs over a period of weeks and may be influenced by interstitial Aβ concentration as well as reactive gliosis.
Received June 5, 2009;
revised July 17, 2009;
accepted July 18, 2009.
Correspondence should be addressed to Dr. Jin-Moo Lee, Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box: 8111, St. Louis, MO 63110. Email: leejm{at}neuro.wustl.edu
This article has been cited by other articles:

|
 |

|
 |
 
J.-E. Kang, M. M. Lim, R. J. Bateman, J. J. Lee, L. P. Smyth, J. R. Cirrito, N. Fujiki, S. Nishino, and D. M. Holtzman
Amyloid-{beta} Dynamics Are Regulated by Orexin and the Sleep-Wake Cycle
Science,
November 13, 2009;
326(5955):
1005 - 1007.
[Abstract]
[Full Text]
[PDF]
|
 |
|