Young donor immune cells may aid cognition in aged mice
In experiments in aged mice, blocking a receptor for a protein that supports nerve cells impaired cognitive improvements after young donor bone marrow transplants.
Limit: Cognitive effects were assessed only one or three months after transplantation
Edited by Boris Djordjevic · AgingResearch.News
In an experiment in aged mice, researchers transplanted bone marrow from young donors, then selectively removed donor-derived immune cells from the brain one or three months later. These cells resembled microglia, the brain’s resident immune cells.
At one month, donor cells were abundant in the hippocampus, a brain region involved in memory. Removing them severely impaired improvements in cognitive function. Blocking the receptor for brain-derived neurotrophic factor, a protein that supports nerve cells, also impaired cognitive improvements. At three months, removal did not affect behavior dependent on the hippocampus, presumably because donor cells were absent there. The findings suggested that young donor cells could improve cognitive function through this signaling pathway early after entering the brain, without needing to remain permanently.
Why it matters
Brain immune cells can become more inflammatory with age. The work addresses whether supporting cognitive function in the aging brain requires lasting replacement of immune cells or signals delivered early after transplantation.
Caveats
These animal experiments do not show whether the approach would benefit people. The paper is a preprint and has not been peer-reviewed.
- Donor bone marrow-derived macrophage ablation
- Young bone marrow-derived microglia-like cells
- NTRK2
- BDNF signaling
- Cognitive decline
- Mice
The paper
Toronto General Research Institute
bioRxiv, Oct 21, 2026, Open access, CC BY, Preprint, not peer-reviewed
