The marmoset as an important primate model for longitudinal studies of neurocognitive aging. Issue 11 (21st May 2021) - Rothwell, Emily S.
Abstract: Age‐related cognitive decline has been extensively studied in humans, but the majority of research designs are cross‐sectional and compare across younger and older adults. Longitudinal studies are necessary to capture variability in cognitive aging trajectories but are difficult to carry out in humans and long‐lived nonhuman primates. Marmosets are an ideal primate model for neurocognitive aging as their naturally short lifespan facilitates longitudinal designs. In a longitudinal study of marmosets tested on reversal learning starting in middle‐age, we found that, on average, the group of marmosets declined in cognitive performance around 8 years of age. However, we found highly variable patterns of cognitive aging trajectories across individuals. Preliminary analyses of brain tissues from this cohort also show highly variable degrees of neuropathology. Future work will tie together behavioral trajectories with brain pathology and provide a window into the factors that predict age‐related cognitive decline. Abstract : Individual marmosets displayed highly variable patterns of cognitive aging trajectories across a 4‐year longitudinal study. Research Highlights: Longitudinal studies of neurocognitive aging in nonhuman primates are needed to understand healthy and pathological human aging. Marmosets have a naturally short lifespan and are ideal for longitudinal designs. Marmosets show highly variable patterns of cognitive aging trajectories as well as varying degrees of pathology in postmortem brain tissues. Heterogeneity of neurocognitive aging patterns provides a window into predictors of cognitive decline.