Article

APP/PS1KI bigenic mice develop early synaptic deficits and hippocampus atrophy.

Division of Molecular Psychiatry, Department of Psychiatry, Alzheimer Ph.D. Graduate School, University of Goettingen, Goettingen, Germany.
Acta Neuropathologica (impact factor: 9.32). 05/2009; 117(6):677-85. DOI:10.1007/s00401-009-0539-7 pp.677-85
Source: PubMed

ABSTRACT Abeta accumulation has an important function in the etiology of Alzheimer's disease (AD) with its typical clinical symptoms, like memory impairment and changes in personality. However, the mode of this toxic activity is still a matter of scientific debate. We used the APP/PS1KI mouse model for AD, because it is the only model so far which develops 50% hippocampal CA1 neuron loss at the age of 1 year. Previously, we have shown that this model develops severe learning deficits occurring much earlier at the age of 6 months. This observation prompted us to study the anatomical and cellular basis at this time point in more detail. In the current report, we observed that at 6 months of age there is already a 33% CA1 neuron loss and an 18% atrophy of the hippocampus, together with a drastic reduction of long-term potentiation and disrupted paired pulse facilitation. Interestingly, at 4 months of age, there was no long-term potentiation deficit in CA1. This was accompanied by reduced levels of pre- and post-synaptic markers. We also observed that intraneuronal and total amount of different Abeta peptides including N-modified, fibrillar and oligomeric Abeta species increased and coincided well with CA1 neuron loss. Overall, these data provide the basis for the observed robust working memory deficits in this mouse model for AD at 6 months of age.

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Keywords

33% CA1 neuron loss
 
4 months
 
6 months
 
Alzheimer's disease
 
APP/PS1KI mouse model
 
CA1 neuron loss
 
current report
 
develops 50% hippocampal CA1 neuron loss
 
different Abeta peptides
 
drastic reduction
 
long-term potentiation deficit
 
memory deficits
 
memory impairment
 
mouse model
 
observed robust
 
oligomeric Abeta species
 
paired pulse facilitation
 
total amount
 
toxic activity
 
typical clinical symptoms