Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology

Citation

Gräßle T, Crockford C, Eichner C, Girard‐Buttoz C, Jäger C, Kirilina E, Lipp I, Düx A, Edwards L, Jauch A, Kopp KS, Paquette M, Pine K, Haun DBM, Fedurek P & et al. (2023) Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology. Methods in Ecology and Evolution. https://doi.org/10.1111/2041-210x.14039

Abstract
The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviours such as language and sophisticated tool use. To understand this evolution, a diverse sample set of humans' closest relatives with varying socio-ecologies is needed. However, current brain banks predominantly curate brains from primates that died in zoological gardens. We try to address this gap by establishing a field pipeline mitigating the challenges associated with brain extractions of wild primates in their natural habitat. The success of our approach is demonstrated by our ability to acquire a novel brain sample of deceased primates with highly variable socio-ecological exposure and a particular focus on wild chimpanzees. Methods in acquiring brain tissue from wild settings are comprehensively explained, highlighting the feasibility of conducting brain extraction procedures under strict biosafety measures by trained veterinarians in field sites. Brains are assessed at a fine-structural level via high-resolution MRI and state-of-the-art histology. Analyses confirm that excellent tissue quality of primate brains sourced in the field can be achieved with a comparable tissue quality of brains acquired from zoo-living primates. Our field methods are noninvasive, here defined as not harming living animals, and may be applied to other mammal systems than primates. In sum, the field protocol and methodological pipeline validated here pose a major advance for assessing the influence of socio-ecology on medium to large mammal brains, at both macro- and microstructural levels as well as aiding with the functional annotation of brain regions and neuronal pathways via specific behaviour assessments.

Keywords
brain connectivity; brain evolution; brain extraction; brain microstructure; field necropsy; MRI; socio-ecological factors

Notes
Output Status: Forthcoming/Available Online Additional authors: Richard McElreath, Alfred Anwander, Philipp Gunz, Markus Morawski, Angela D. Friederici, Nikolaus Weiskopf, Fabian H. Leendertz, Roman M. Wittig EBC Cosortium: Karoline Albig, Bala Amarasekaran, Sam Angedakin, Alfred Anwander, Daniel Aschoff, Caroline Asiimwe, Laurent Bailanda, Jacinta C. Beehner, Raphael Belais, Thore J. Bergman, Birgit Blazey, Andreas Bernhard, Christian Bock, Pénélope Carlier, Julian Chantrey, Catherine Crockford, Tobias Deschner, Ariane Düx1, Luke Edwards, Cornelius Eichner, Géraldine Escoubas2, Malak Ettaj, Karina Flores, Richard Francke, Angela D. Friederici, Cédric Girard-Buttoz, Jorge Gomez Fortun, Zoro Bertin GoneBi, Tobias Gräßle, Eva Gruber-Dujardin, Philipp Gunz, Jess Hartel, Daniel B. M. Haun, Michael Henshall, Catherine Hobaiter, Noémie Hofman, Jenny E. Jaffe, Carsten Jäger, Anna Jauch, Stomy Kahemere, Evgeniya Kirilina, Robert Klopfleisch, Tobias Knauf-Witzens, Kathrin S. Kopp, Guy Landry Mamboundou Kouima, Bastian Lange, Kevin Langergraber, Arne Lawrenz, Fabian H. Leendertz, Ilona Lipp, Matys Liptovszky, Tobias Loubser Theron, Christelle Patricia Lumbu, Patrice Makouloutou Nzassi, Kerstin Mätz-Rensing, Richard McElreath, Matthew McLennan, Zoltan Mezö, Sophie Moittie, Torsten Møller, Markus Morawski, David Morgan, Timothy Mugabe, Martin Muller, Matthias Müller, Inoussa Njumboket, Karin Olofsson-Sannö, Alain Ondzie, Emily Otali, Michael Paquette, Simone Pika, Kerrin Pine, Andrea Pizarro, Kamilla Pléh, Jessica Rendel, Sandra Reichler-Danielowski, Martha M. Robbins, Alejandra Romero Forero, Konstantin Ruske, Liran Samuni, Crickette Sanz, André Schüle, Ingo Schwabe, Katarina Schwalm, Sheri Speede, Lara Southern, Jonas Steiner, Marc Stidworthy, Martin Surbeck, Claudia Szentiks, Tanguy Tanga, Reiner Ulrich, Steve Unwin, Erica van de Waal, Sue Walker, Nikolaus Weiskopf, Gudrun Wibbelt, Roman M. Wittig, Kim Wood, Klaus Zuberbühler

Journal
Methods in Ecology and Evolution

• Methods Ecol Evol - 2023 - Gr Le - Sourcing High Tissue Quality Brains From Deceased Wild Primates With Known