Near infrared light decreases synaptic vulnerability to amyloid beta oligomers

Sci Rep. 2017 Nov 8;7(1):15012. doi: 10.1038/s41598-017-15357-x.

Abstract

Synaptic dysfunction due to the disrupting binding of amyloid beta (Aβ) and tau oligomers is one of the earliest impairments in Alzheimer's Disease (AD), driving initial cognitive deficits and clinical manifestation. Consequently, there is ample consensus that preventing early synaptic dysfunction would be an effective therapeutic strategy for AD. With this goal in mind, we investigated the effect of a treatment of mice with near infrared (NIR) light on synaptic vulnerability to Aβ oligomers. We found that Aβ oligomer binding to CNS synaptosomes isolated from wild type (wt) mice treated with NIR light was significantly reduced and the resulting suppression of long term potentiation (LTP) by Aβ oligomers was prevented. Similarly, APP transgenic mice treated with NIR showed a significant reduction of endogenous Aβ at CNS synapses. We further found that these phenomena were accompanied by increased synaptic mitochondrial membrane potential in both wt and Tg2576 mice. This study provides evidence that NIR light can effectively reduce synaptic vulnerability to damaging Aβ oligomers, thus furthering NIR light therapy as a viable treatment for AD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism
  • Alzheimer Disease / physiopathology
  • Alzheimer Disease / radiotherapy
  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Peptides / toxicity
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Disease Models, Animal
  • Female
  • Humans
  • Infrared Rays*
  • Long-Term Potentiation / drug effects
  • Long-Term Potentiation / physiology
  • Long-Term Potentiation / radiation effects
  • Male
  • Membrane Potential, Mitochondrial / drug effects
  • Membrane Potential, Mitochondrial / radiation effects
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Protein Binding / radiation effects*
  • Synapses / metabolism*
  • Synaptosomes / metabolism
  • Synaptosomes / radiation effects

Substances

  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor