Detailed mapping of the complex fiber structure and white matter pathways of the chimpanzee brain
Cornelius Eichner, Michael Paquette, Christa Müller-Axt, Christian Bock, Eike Budinger, Tobias Gräßle, Carsten Jäger, Evgeniya Kirilina, Ilona Lipp, Data Analysis and Writing, Brain Extraction, Torsten Möller, Karin Olofsson‐Sannö, Markus Morawski, Henriette Rusch, Patricia Wenk, Nikolaus Weiskopf, Roman M. Wittig, Catherine Crockford, Angela D. Friederici, Alfred Anwander
Abstract
Long-standing questions about human brain evolution may only be resolved through comparisons with close living evolutionary relatives, such as chimpanzees. This applies in particular to structural white matter (WM) connectivity, which continuously expanded throughout evolution. However, due to legal restrictions on chimpanzee research, neuroscience research currently relies largely on data with limited detail or on comparisons with evolutionarily distant monkeys. Here, we present a detailed magnetic resonance imaging resource to study structural WM connectivity in the chimpanzee. This open-access resource contains (1) WM reconstructions of a postmortem chimpanzee brain, using the highest-quality diffusion magnetic resonance imaging data yet acquired from great apes; (2) an optimized and validated method for high-quality fiber orientation reconstructions; and (3) major fiber tract segmentations for cross-species morphological comparisons. This dataset enabled us to identify phylogenetically relevant details of the chimpanzee connectome, and we anticipate that it will substantially contribute to understanding human brain evolution.