Microglial analysis in whole‐mount retina of Alzheimer's disease 3xTg‐AD mouse model

Abstract

AbstractPurposeAlzheimer’s Disease (AD) is a primary degenerative disease that is characterized by the accumulation of β‐amyloid and tau in central nervous system, even in visual brain areas and in the retina. This raises the possibility that tracking changes in the retina can be used to assess neurodegeneration in AD.MethodsWe analysed the retinas of 16‐month‐old 3xTg‐AD transgenic mice, which are used as an animal model of AD, and wild‐type (C57BL6/129S). Whole mount retinas were stained with antibodies against Iba‐1 and OX‐6. The morphology, number and soma size of microglia in the retina were analysed.ResultsRetinas from 3xTg‐AD transgenic mice showed signs of microglial activation relative to retinas from wild‐type animals: greater number of microglia, thickening of microglial soma, retraction of microglial processes and migration of microglia within and between layers. This activation was associated with alterations in the microglial plexus in the external plexiform layer and in the complex of internal layers. Retinas from 3xTg‐AD mice showed circular groups of microglia that reoriented and polarized their processes differently than in control retinas. Moreover, it was found a significant increase in both the number and cell body area of Iba‐1+ cells in 3xTg‐AD retinas in comparison with wild‐type retinas.ConclusionsRetinas from a mouse model of AD show signs of microglial activation. Reactive gliosis caused by AD‐associated protein aggregation may trigger morphological changes in the retinas of AD patients.AcknowledgmentsSanta Casa Mantero Belard Award 2015 (MB‐1049‐2015), Foundation for Science and Technology (PEst UID/NEU/04539/2013), COMPETE‐FEDER (POCI‐01‐0145‐FEDER‐007440), and Centro 2020 Regional Operational Programme (CENTRO‐01‐0145‐FEDER‐000008: BrainHealth 2020).