Tag Archives: National Chimpanzee Brain Resource

Primates brain shape

We have published one more paper on the morphology of the precuneus, this time featuring a sample of non-human primates, in collaboration with James Rilling and Todd Preuss from the Emory University (Atlanta, USA). Modern humans have a much larger precuneus than chimpanzees both in absolute and relative size. Taking into account the large brain size in our species, we investigated the midsagittal morphology in non-human primates as to test whether precuneus proportions are influenced by allometric factors. We did a geometric morphometric analysis on a total of 42 MRIs from the National chimpanzee brain resource database, including 5 species of apes and 4 species of monkeys. A first analysis, conducted on the species averages, showed that the main pattern of midsagittal variation involves the general shape of the braincase, which might be due to cranial constraints rather than to changes in proportions of specific brain regions. This main shape pattern separates monkeys from apes, as the former display flatter, elongated brains (with capuchins being the flattest), while the latter exhibit rounder brains with frontal bulging (especially orangutans). This morphological variation correlates with brain size, except for gorillas (which brain is large but elongated), and gibbons (which have smaller but round brains). A second analysis was conducted only on chimpanzees and macaques, to compare two species with different brain size. In neither case the proportions of the precuneus displayed major differences between species or size-related changes. However, as in humans, precuneus size is very variable within each species, suggesting a remarkable plasticity. Overall, the results suggest that precuneus expansion in modern humans is a species-specific characteristic of our species, rather than a simple consequence of increase in brain size. Further studies should address the histological and functional processes involved in this morphological change.

Sofia Pedro


Chimp brains

NCBSDear colleagues,
We are very pleased to announce the launch of the National Chimpanzee Brain Resource (NCBR) website. The NCBR is supported by the National Institute of Neurological Disorders and Stroke. We encourage you to browse the site, where you will find information about MRI datasets and tissue samples that are available by request to researchers. The NCBR website also serves as a data repository for studies that include chimpanzee brains. In the near future, the NCBR website will grow with the addition of a searchable database of behavioral and cognitive tasks, pedigrees, rearing history, neuroimaging data, and postmortem brain samples; chimpanzee brain atlas tools; and educational information about chimpanzee neuroscience. We invite you to make a request for MRI data or tissue. Please contribute your datasets that include chimpanzee brains to the repository. Our aim is for the NCBR to facilitate research advancement through the distribution of chimpanzee brain resources and dissemination of information, promoting the value of chimpanzees as a comparative reference to better understand the structure, function, and evolution of the human brain.

NCBR Directors
Chet Sherwood, Bill Hopkins, Todd Preuss