Microglial morphology reflects cognitive status in the aging rat brain

Area of Science:

• Neuroscience
• Immunology
• Aging Research

Background:

• Age-related cognitive decline is a widespread issue with unclear cellular mechanisms.
• Microglia, the brain's immune cells, exhibit morphological changes with aging, potentially linked to cognitive dysfunction.
• The precise relationship between microglial morphology and cognitive function in specific brain regions is not well understood.

Purpose of the Study:

• To investigate the link between microglial morphology-based phenotypes and cognitive performance across various domains affected by aging.
• To identify distinct microglial subtypes based on morphology and their association with cognitive function.

Main Methods:

• Analysis of microglial morphology in four cognitive brain regions of rats at 3, 9, and 15 months of age.
• Hierarchical clustering on principal components was used to identify microglial subtypes.
• Cognitive performance was assessed using the radial arm water maze and T-maze set-shifting tasks.

Main Results:

• Observed age-related cognitive impairments in rats.
• Identified region-specific alterations in microglial morphotype abundance correlating with age.
• Found significant correlations between the abundance of specific microglial clusters and cognitive performance in the prefrontal cortex, orbitofrontal cortex, and hippocampus.

Conclusions:

• Morphological profiling effectively captures microglial heterogeneity in the aging brain.
• Changes in microglial morphology are associated with age-related cognitive decline.
• These findings suggest that microglial morphological alterations may play a role in, or reflect, cognitive dysfunction during aging.