Abstract
Humans and chimpanzees are genetically similar and share a number of life history, behavioral, cognitive and neuroanatomical similarities. Notwithstanding, our understanding of age-related changes in cognitive and motor functions in chimpanzees remains largely unstudied despite recent evident demonstrating that chimpanzees exhibit many of the same neuropathological features of Alzheimer's disease observed in human postmortem brains. Here, we examined age-related differences in cognition and cortical thickness measured from magnetic resonance images in a sample of 215 chimpanzees ranging in age between 9 and 54 years. We found that chimpanzees showed global and region-specific thinning of cortex with increasing age. Further, within the elderly cohort, chimpanzees that performed better than average had thicker cortex in frontal, temporal and parietal regions compared to chimpanzees that performed worse than average. Independent of age, we also found sex differences in cortical thickness in 4 brain regions. Males had higher adjusted cortical thickness scores for the caudal anterior cingulate, rostral anterior cingulate, and medial orbital frontal while females had higher values for the inferior parietal cortex. We found no evidence that increasing age nor sex was associated with asymmetries in cortical thickness. Moreover, age-related differences in cognitive function were only weakly associated with asymmetries in cortical thickness. In summary, as has been reported in humans and other primates, elderly chimpanzees show thinner cortex and variation in cortical thickness is associated with general cognitive functions.
Original language | English |
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Journal | Neurobiology of Aging |
Volume | 126 |
Pages (from-to) | 91-102 |
ISSN | 0197-4580 |
DOIs | |
Publication status | Published - 2023 |
Bibliographical note
Funding Information:WDH designed study, performed statistical analyses, wrote the manuscript. XI and Roberts performed all image processing in Freesurfer, CCS, MAR and MKE assisted in research design and manuscript preparation, MMM and SJS helped with data collection, analysis and manuscript preparation. The authors have no actual or potential conflicts of interest. This research was supported in part by NIH grants NS-073134, AG-067419 and NS-092988 (support for the National Chimpanzee Brain Resource). Chimpanzee maintenance at the National Center for Chimpanzee Care is funded by NIH/NCRR U42-OD-011197. MMM is funded by NIH grant AG-078411. American Psychological Association guidelines for the ethical treatment of animals were adhered to during all aspects of this study. We are grateful to the entire veterinary staffs at the NCCC and YNPRC for their helpful assistance in collection of the MRI scans.
Funding Information:
This research was supported in part by NIH grants NS-073134, AG-067419 and NS-092988 (support for the National Chimpanzee Brain Resource ). Chimpanzee maintenance at the National Center for Chimpanzee Care is funded by NIH/NCRR U42-OD-011197 . MMM is funded by NIH grant AG-078411. American Psychological Association guidelines for the ethical treatment of animals were adhered to during all aspects of this study. We are grateful to the entire veterinary staffs at the NCCC and YNPRC for their helpful assistance in collection of the MRI scans.
Keywords
- Aging, Cognition
- Asymmetry
- Chimpanzees
- Cortical Thickness