Active Genetics & Molecular Biology Brain & Nervous System

Life-History Trade-Offs in Wild Mice: Reproductive Investment, IGF-1, Cognition and the Costs of Aging

Funder Wellcome Charity-funded
Recipient organisation University of Edinburgh
Funding Not disclosed
Period Oct 2025 — Sept 2028

In plain English

AI plain-English summary

Wild wood mice on a Scottish island will have their reproduction experimentally reduced to test whether having fewer offspring slows down the rate of ageing. Why this matters: Scientists know that animals that invest heavily in reproduction often age faster and die younger, but the biological mechanisms behind this trade-off remain unclear. This project targets a specific hormone—insulin-like growth factor 1 (IGF-1)—that promotes growth and fertility but may also accelerate cognitive decline and shorten lifespan. By combining long-term field data, epigenetic clocks, and controlled experiments in wild mice, the researchers aim to untangle cause from correlation. If the research succeeds, it will reveal fundamental mechanisms linking reproduction, ageing, and cognitive decline that apply across mammals, including humans. This is primarily curiosity-driven fundamental science, but understanding how IGF-1 mediates trade-offs between fertility and brain health could eventually inform strategies for managing age-related cognitive decline or optimising reproductive health. Similar fundamental work on ageing mechanisms in short-lived animals has previously uncovered pathways—like calorie restriction and IGF signalling—that now guide human healthspan research.

View original technical description
Senescence, the progressive decline in biological function, varies among individuals due to genetic, environmental, and life-history traits. A critical challenge in aging biology is understanding how reproductive investment affects senescence, survival, and cognitive decline. Life-history trade-offs theory suggests that energy devoted to growth and reproduction reduces somatic maintenance, resulting in accelerated aging. A candidate mechanism underpinning these trade-offs is the insulin-like growth factor 1 (IGF-1), which promotes growth and fecundity, shortens lifespan and alters cognition. This project uses wild wood mice (Apodemus sylvaticus) to investigate how reproductive investment shapes individual variation in senescence and cognition, and IGF-1’s role in mediating these processes. Using epigenetic clocks, survival monitoring, and longitudinal datasets, we will quantify links between reproduction, senescence and survival. Experimental reduction of reproduction in wild females will test whether lower investment slows senescence. Parallel studies will measure IGF-1 levels in relation to reproduction and aging, both in lab-reared and wild populations. Finally, we will test whether reproductive trade-offs and IGF-1 predict cognitive decline patterns, using molecular biomarkers (e.g., NfL, targeted epigenetic markers) and behavioural proxies. These findings will reveal the mechanisms linking reproduction, senescence and cognition, with implications for aging biology, health management and conservation.

View the original record at the funder ↗

Researchers

Samantha Browne (EPMC Awardee)

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Original classification

PhD Studentship (Basic)

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