Brain immune cells in mice differ in response to shared blood
An analysis of four mouse brain regions found the cerebellum most responsive and the striatum least responsive when mice shared young or old blood.
Limit: Only two heterochronic and three isochronic parabiosis animal pairs were analyzed
Stake: An author works for Daiichi Sankyo.
Edited by Boris Djordjevic · AgingResearch.News
In mice, researchers analyzed microglia, the brain’s immune cells, using existing data from aging comparisons and an animal experiment that surgically joined mice to share circulation. The aging dataset included three mice aged 3–4 months and six aged 18–24 months. The shared-circulation experiment used male mice aged 2 or 26 months, in three same-age pairs and two young–old pairs.
The team examined gene activity in individual cells and identified eight microglial states, along with a shared set of activation-related genes. The four brain regions differed in their mix of cell states and age-related changes. Microglia in the cerebellum were most responsive to exposure to young or old blood, while those in the striatum responded minimally. In older mice exposed to young blood, some age-related gene activity changes shifted in the opposite direction, most notably in the cerebellum.
Why it matters
Microglia contribute to the progression of neurodegenerative diseases, for which aging is a major risk factor. The authors suggest their work could inform strategies targeting these cells to modulate brain aging.
Caveats
Gene-activity changes do not by themselves establish improved brain function. The shared-circulation experiment included only two young–old mouse pairs, and the findings do not establish benefits in people.
From the paper
- Limitation
Given that region-specific and age-related changes in gene expression may vary among species, the conclusions drawn from mouse data may not be fully translatable to humans.
Quoted word for word from the full text on PubMed Central.
The paper
Washington University in St. Louis
Cell Reports, Aug 28, 2026, Open access
Presented at AAIC 2025 as an abstract
