title: Differential prefrontal white matter development in chimpanzees and humans.
abstract: A comparison of developmental patterns of white matter (WM) within the prefrontal region between humans and nonhuman primates is key to understanding human brain evolution. WM mediates complex cognitive processes and has reciprocal connections with posterior processing regions [1, 2]. Although the developmental pattern of prefrontal WM in macaques differs markedly from that in humans [3], this has not been explored in our closest evolutionary relative, the chimpanzee. The present longitudinal study of magnetic resonance imaging scans demonstrated that the prefrontal WM volume in chimpanzees was immature and had not reached the adult value during prepuberty, as observed in humans but not in macaques. However, the rate of prefrontal WM volume increase during infancy was slower in chimpanzees than in humans. These results suggest that a less mature and more protracted elaboration of neuronal connections in the prefrontal portion of the developing brain existed in the last common ancestor of chimpanzees and humans, and that this served to enhance the impact of postnatal experiences on neuronal connectivity. Furthermore, the rapid development of the human prefrontal WM during infancy may help the development of complex social interactions, as well as the acquisition of experience-dependent knowledge and skills to shape neuronal connectivity.
authors.affiliation: Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sakai
authors.forename: Akichika
authors.initials: A
authors.lastname: Mikami
authors.forename: Masaki
authors.initials: M
authors.lastname: Tomonaga
authors.forename: Mie
authors.initials: M
authors.lastname: Matsui
authors.forename: Juri
authors.initials: J
authors.lastname: Suzuki
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Hamada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takako
authors.initials: T
authors.lastname: Miyabe-Nishiwaki
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Makishima
authors.forename: Masato
authors.initials: M
authors.lastname: Nakatsukasa
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Matsuzawa
mesh_terms: D000818:Animals; D005075:Biological Evolution; D006801:Humans; D008137:Longitudinal Studies; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging / Q000379:methods; D009413:Nerve Fibers, Myelinated; D002679:Pan troglodytes / Q000033:anatomy & histology* / Q000254:growth & development*; D017397:Prefrontal Cortex / Q000033:anatomy & histology* / Q000254:growth & development*