Brain structure variation in great apes, with attention to the mountain gorilla (Gorilla beringei beringei)

Authors

  • Chet C. Sherwood,

    Corresponding author
    1. Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio
    2. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
    • Department of Anthropology, Kent State University, 226 Lowry Hall, Kent, OH 44242-0001
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  • Michael R. Cranfield,

    1. Mountain Gorilla Veterinary Project, Ruhengeri, Rwanda
    2. Medical Department, Baltimore Zoo, Baltimore, Maryland
    3. Division of Comparative Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland
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  • Patrick T. Mehlman,

    1. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
    2. Dian Fossey Gorilla Fund International, Atlanta, Georgia
    3. Department of Anthropology, SUNY at Stony Brook, New York, New York
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  • Alecia A. Lilly,

    1. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
    2. Dian Fossey Gorilla Fund International, Atlanta, Georgia
    3. Department of Anthropology, SUNY at Stony Brook, New York, New York
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  • Jo Anne L. Garbe,

    1. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
    2. Mountain Gorilla Veterinary Project, Ruhengeri, Rwanda
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  • Christopher A. Whittier,

    1. Mountain Gorilla Veterinary Project, Ruhengeri, Rwanda
    2. Environmental Medicine Consortium and Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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  • Felicia B. Nutter,

    1. Mountain Gorilla Veterinary Project, Ruhengeri, Rwanda
    2. Environmental Medicine Consortium and Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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  • Thomas R. Rein,

    1. Department of Neuroscience, Mount Sinai School of Medicine, New York, New York
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  • Harlan J. Bruner,

    1. Department of Neuroscience, Mount Sinai School of Medicine, New York, New York
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  • Ralph L. Holloway,

    1. Department of Anthropology, Columbia University, New York, New York
    2. New York Consortium in Evolutionary Primatology, New York, New York
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  • Cheuk. Y. Tang,

    1. Department of Radiology, Mount Sinai School of Medicine, New York, New York
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  • Thomas P. Naidich,

    1. Department of Radiology, Mount Sinai School of Medicine, New York, New York
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  • Bradley N. Delman,

    1. Department of Radiology, Mount Sinai School of Medicine, New York, New York
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  • H. Dieter Steklis,

    1. Dian Fossey Gorilla Fund International, Atlanta, Georgia
    2. Department of Anthropology, Rutgers University, New Brunswick, New Jersey
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  • Joseph M. Erwin,

    1. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
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  • Patrick R. Hof

    1. Foundation for Comparative and Conservation Biology, Hagerstown, Maryland
    2. Department of Neuroscience, Mount Sinai School of Medicine, New York, New York
    3. New York Consortium in Evolutionary Primatology, New York, New York
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Abstract

This report presents data regarding the brain structure of mountain gorillas (Gorilla beringei beringei) in comparison with other great apes. Magnetic resonance (MR) images of three mountain gorilla brains were obtained with a 3T scanner, and the volume of major neuroanatomical structures (neocortical gray matter, hippocampus, thalamus, striatum, and cerebellum) was measured. These data were included with our existing database that includes 23 chimpanzees, three western lowland gorillas, and six orang-utans. We defined a multidimensional space by calculating the principal components (PCs) from the correlation matrix of brain structure fractions in the well-represented sample of chimpanzees. We then plotted data from all of the taxa in this space to examine phyletic variation in neural organization. Most of the variance in mountain gorillas, as well as other great apes, was contained within the chimpanzee range along the first two PCs, which accounted for 61.73% of the total variance. Thus, the majority of interspecific variation in brain structure observed among these ape taxa was no greater than the within-species variation seen in chimpanzees. The loadings on PCs indicated that the brain structure of great apes differs among taxa mostly in the relative sizes of the striatum, cerebellum, and hippocampus. These findings suggest possible functional differences among taxa in terms of neural adaptations for ecological and locomotor capacities. Importantly, these results fill a critical gap in current knowledge regarding great ape neuroanatomical diversity. Am. J. Primatol. 63:149–164, 2004. © 2004 Wiley-Liss, Inc.

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