Abstract # 6142 Poster # 181:

Scheduled for Friday, June 19, 2015 06:00 PM-08:00 PM: (Cascade AJBCD) Poster Presentation


EARLY SOCIAL ENVIRONMENT AND SEX ARE ASSOCIATED WITH WHITE MATTER ASYMMETRIES IN THE FRONTO-INSULAR CORTEX OF CHIMPANZEES (PAN TROGLODYTES)

K. R. Davidek1,2,3, J. Taglialatela4, C. Sherwood3 and W. D. Hopkins1,2
1Georgia State University, Atlanta, Georgia, USA, 2Yerkes National Primate Research Center, 3George Washington University, 4Kennesaw State University
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     The insula, a lobe of the cerebral cortex, participates in various integrative perceptual and cognitive processes as part of the salience network. Von Economo neurons (VENs), a derived class of spindle-shaped projection neurons implicated in self-awareness and social cognition, are found in the fronto-insular (FI) cortex of humans and great apes. Here, we quantified white matter connections between FI and the entire cortex in order to understand its role in the salience network. We calculated volumes of FI white matter connections in vivo using diffusion tensor imaging (DTI) in 49 chimpanzees (Pan troglodytes) (males: n=20, females: n=29). We defined FI based on probabilistic mapping of its location from cytoarchitectural identification of VEN distribution in 11 post-mortem brains. Our results indicate connections between FI and regions comprising the salience and social cognition circuits (e.g. medial and superior temporal gyri, prefrontal cortex, and frontal pole). Additionally, we performed mixed-model ANOVAs to examine sex and rearing effects on volumes of FI connections (mother-reared: n=19; human-reared: n=30). Males show greater volumes of white matter connections in the left hemisphere compared to females (F(1,45)=4.891; p=0.032). We also found that human-reared individuals display rightward asymmetries (F(1,45)=5.247; p=0.027) while mother-reared chimpanzees showed the opposite pattern. These results highlight the impact of early social experience on cortical white matter development.