title: Planum temporale asymmetries correlate with corpus callosum axon fiber density in chimpanzees (Pan troglodytes).
abstract: The corpus callosum (CC) is the major white matter tract that connects the two cerebral hemispheres. Some have theorized that individual differences in behavioral and brain asymmetries are linked to variation in the density of axon fibers that traverse different sections of the CC. In this study, we examined whether variation in axon fiber density in the CC was associated with variation in asymmetries in the planum temporale (PT) in a sample of 20 post-mortem chimpanzee brains. We further tested for sex differences in small and large CC fiber proportions and density in the chimpanzees. We found that the distribution of small and large fibers within the CC of chimpanzees follows a similar pattern to those reported in humans. We also found that chimpanzees with larger asymmetries in the PT had fewer large fibers in the posterior portion of the CC, particularly among females. As has been reported in human brains, the findings reported here indicate that individual differences in brain asymmetries are associated with variation in interhemispheric connectivity as manifest in axon fiber density and size.
authors: Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322, United States. whopkin@emory.edu
authors: William D
authors: WD
authors: Hopkins
authors: John F
authors: JF
authors: Pilger
authors: Rachel
authors: R
authors: Storz
authors: Alex
authors: A
authors: Ambrose
authors: Patrick R
authors: PR
authors: Hof
authors: Chet C
authors: CC
authors: Sherwood
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D003337:Corpus Callosum / Q000033:anatomy & histology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D002679:Pan troglodytes / Q000033:anatomy & histology*; D012737:Sex Factors; D013693:Temazepam
chemical_list: D013693:Temazepam