Altered neurotransmission in the lateral amygdala in aged human apoE4 targeted replacement mice.

Published

Journal Article

The human APOE4 allele is associated with an early age of onset and increased risk of Alzheimer's disease (AD). Apolipoprotein E is secreted as part of a high-density lipoprotein-like particle by glial cells in the brain for the primary purpose of transport of lipophilic compounds involved in the maintenance of synapses. Previous studies examining synaptic integrity in the amygdala of human apoE targeted replacement (TR) mice showed a decrease in spontaneous excitatory synaptic activity, dendritic arbor, and spine density associated with apoE4 compared with apoE3 and apoE2 in adult male mice. In the present study, we assessed how APOE genotype affects synaptic integrity of amygdala neurons by comparing electrophysiological and morphometric properties in human apoE3, E4, and E2/4 TR mice at the age of 18-20 months. In contrast to adult mice, we found that aged apoE4 TR mice exhibited the highest level of excitatory synaptic activity compared with other cohorts. Additionally, apoE4 mice had significantly greater spontaneous inhibitory activity than all other cohorts. Taken together, there was a significant interaction between genotypes when comparing inhibition relative to excitation; there was a simple main effect of frequency type with an imbalance toward inhibition in apoE4 mice but not in apoE3 or apoE2/4 mice. These results suggest that apoE isoforms differentially influence synaptic transmission throughout the life span, where aging coupled with apoE4 expression, results in an imbalance in maintaining integrity of synaptic transmission.

Full Text

Duke Authors

Cited Authors

  • Klein, RC; Acheson, SK; Mace, BE; Sullivan, PM; Moore, SD

Published Date

  • September 2014

Published In

Volume / Issue

  • 35 / 9

Start / End Page

  • 2046 - 2052

PubMed ID

  • 24698766

Pubmed Central ID

  • 24698766

Electronic International Standard Serial Number (EISSN)

  • 1558-1497

Digital Object Identifier (DOI)

  • 10.1016/j.neurobiolaging.2014.02.019

Language

  • eng

Conference Location

  • United States