Acitretin reverses early functional network degradation in a mouse model of familial Alzheimer's disease

Sci Rep. 2021 Mar 23;11(1):6649. doi: 10.1038/s41598-021-85912-0.

Abstract

Aberrant activity of local functional networks underlies memory and cognition deficits in Alzheimer's disease (AD). Hyperactivity was observed in microcircuits of mice AD-models showing plaques, and also recently in early stage AD mutants prior to amyloid deposition. However, early functional effects of AD on cortical microcircuits remain unresolved. Using two-photon calcium imaging, we found altered temporal distributions (burstiness) in the spontaneous activity of layer II/III visual cortex neurons, in a mouse model of familial Alzheimer's disease (5xFAD), before plaque formation. Graph theory (GT) measures revealed a distinct network topology of 5xFAD microcircuits, as compared to healthy controls, suggesting degradation of parameters related to network robustness. After treatment with acitretin, we observed a re-balancing of those network measures in 5xFAD mice; particularly in the mean degree distribution, related to network development and resilience, and post-treatment values resembled those of age-matched controls. Further, behavioral deficits, and the increase of excitatory synapse numbers in layer II/III were reversed after treatment. GT is widely applied for whole-brain network analysis in human neuroimaging, we here demonstrate the translational value of GT as a multi-level tool, to probe networks at different levels in order to assess treatments, explore mechanisms, and contribute to early diagnosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acitretin / pharmacology*
  • Alzheimer Disease / diagnostic imaging
  • Alzheimer Disease / etiology*
  • Alzheimer Disease / metabolism*
  • Alzheimer Disease / pathology
  • Amyloid beta-Peptides / metabolism
  • Animals
  • Brain / drug effects
  • Brain / metabolism
  • Brain / pathology
  • Brain Waves
  • Calcium / metabolism
  • Disease Models, Animal
  • Humans
  • Immunohistochemistry
  • Mice
  • Neural Pathways / drug effects*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Optical Imaging
  • Plaque, Amyloid / metabolism
  • Plaque, Amyloid / pathology
  • Protein Aggregation, Pathological
  • Synapses / drug effects
  • Synapses / metabolism

Substances

  • Amyloid beta-Peptides
  • Acitretin
  • Calcium