Abstract # 5973 Poster # 169:

Scheduled for Sunday, September 14, 2014 07:00 PM-09:00 PM: Session 22 (Decatur B) Poster Presentation


THE RELATIONSHIP BETWEEN BRAIN VOLUME AND CORPUS CALLOSUM SURFACE AREA IN 7 PRIMATE SPECIES

E. M. Latash1 and W. D. Hopkins1,2
1Georgia State Univeristy, Petit Science Center, Atlanta, GA 30303, USA, 2Yerkes Primate Center
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Neuroanatomical comparison across primate species provides a basis for understanding the evolution of the brain. Magnetic resonance imaging was used to test the hypothesis that the ratio of corpus callosum surface area (CCSA) to brain volume (BV) differs across the seven species. A ratio CCSA to BV in genus Papio (Baboons), Macaca radiata (Bonnet monkeys), Macaca mulatta (Rhesus monkeys), Pan paniscus (Bonobos), genus Gorilla (Gorillas), genus Pongo (Orangutans), and Homo Sapiens (Humas) was compared. Ratios between species varied significantly [ANOVA, alpha=0.05, p=4.8015e-14]. Bonnet monkey and Rhesus monkey ratios of corpus callosum surface area to brain volume varied significantly from the ratios of all of the great apes [Tukey-Kramer HSD, .05]. The great apes did not vary significantly amongst each other. Baboon ratios were not significantly different from any other species of primate. When compared with the Tukey LSD Baboon ratios varied significantly from Bonnet monkeys, Orangutans, and Humans. The ratio of CCSA to BV is aligned with the classification of the great apes and is distinguished from the ratio of monkey species. The surface area of corpus callosum is a measure of the degree of connectivity between the left and right hemispheres of the brain. Our findings support the claim that there is a decrease in the amount of interhemispheric connectivity across the evolution of primate species.