Sex differences in cognitive aging: a 4-year longitudinal study in marmosets

Area of Science:

• Neuroscience
• Primatology
• Gerontology

Background:

• Longitudinal studies are crucial for understanding neurocognitive aging and diseases like Alzheimer's.
• Tracking cognitive changes in long-lived primates is challenging, limiting aging research.
• Common marmosets offer a suitable model due to their shorter lifespan and Alzheimer's-like pathology.

Purpose of the Study:

• To conduct the first longitudinal study of cognitive aging in common marmosets.
• To characterize cognitive aging trajectories from middle to old age.
• To investigate sex differences in cognitive aging patterns.

Main Methods:

• A longitudinal study of 28 marmosets aged approximately 5 to 9 years.
• Cognitive performance was assessed annually using reversal learning tasks with varying stimuli.
• Behavioral measures including motivation, motor skills, and social reactivity were also monitored.

Main Results:

• Marmosets showed initial cognitive improvement, followed by a decline in the final year, suggesting age-related changes.
• Females exhibited earlier cognitive impairment than males, particularly in discrimination tasks.
• Sex differences were not attributable to motivation or motor abilities; females showed a decline in social behavior initiation.

Conclusions:

• Common marmosets exhibit age-related cognitive decline, with sex-specific patterns emerging.
• Individual variability in cognitive aging suggests potential for pathological aging in some individuals.
• Future research linking cognitive trajectories to neuropathology is needed to understand sex-specific aging vulnerabilities.