title: Sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (Pan troglodytes): A combined MRI and DTI analysis.
abstract: Increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. We tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (PT) and different measures of the corpus callosum (CC) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. We found that chimpanzees with larger PT asymmetries in absolute terms had smaller CC surface areas, fewer streamlines and a smaller ratio of fibers to surface area. These results were largely specific to male but not female chimpanzees. Our results partially support the hypothesis that brain asymmetries are linked to variation in corpus callosum morphology, although these associations may be sex-dependent.
authors.affiliation: Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA; Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA. Electronic address: whopkins4@gsu.edu.
authors.forename: William D
authors.initials: WD
authors.lastname: Hopkins
authors.affiliation: Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Hopkins
authors.affiliation: Department of Psychology, Georgia State University, Atlanta, GA 30302, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Misiura
authors.affiliation: Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA.
authors.forename: Elitaveta M
authors.initials: EM
authors.lastname: Latash
authors.affiliation: Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA.
authors.forename: Mary Catherine
authors.initials: MC
authors.lastname: Mareno
authors.affiliation: Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Schapiro
authors.affiliation: Department of Psychology, Trinity University, San Antonio, TX 78212, USA.
authors.forename: Kimberley A
authors.initials: KA
authors.lastname: Phillips
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000502:physiology; D003337:Corpus Callosum / Q000000981:diagnostic imaging* / Q000502:physiology; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D008279:Magnetic Resonance Imaging; D008297:Male; D002679:Pan troglodytes / Q000033:anatomy & histology* / Q000502:physiology; D012727:Sex Characteristics
keywords: Brain asymmetry; Corpus callosum; Planum temporale; Primates