Differences in Frontal Network Anatomy Across Primate Species

• DOI: 10.1523/jneurosci.1650-18.2019
• Publication Date: 2020-01-16T22:49:21Z
• Authors: Rachel L. C. Barrett; Matthew Dawson; Tim B. Dyrby; Kristine Krug; Maurice Ptito; Helen D'Arceuil; Paula L. Croxson; Philippa J. Johnson; Henrietta Howells; Stephanie J. Forkel; Flavio Dell'Acqua; Marco Catani
• Keywords: Frontal lobe; Rhesus macaque; Anterior commissure

The frontal lobe is central to distinctive aspects of human cognition and behavior. Some comparative studies link this a larger cortex even white matter in humans compared with other primates, yet others dispute these findings. discrepancies between could be explained by limitations the methods used quantify volume differences across species, especially when applied connections. In study, we novel tractography approach demonstrate that networks, extending within beyond lobes, occupy 66% total brain 48% three monkey species: vervets (Chlorocebus aethiops), rhesus macaque (Macaca mulatta) cynomolgus fascicularis), all male. simian–human proportional tract were significant for projection, commissural, both intralobar interlobar association tracts. Among long tracts, greatest difference was found tracts involved motor planning, auditory memory, top-down control sensory information, visuospatial attention, no limbic important emotional processing social behaviour. addition, nonfrontal tract, anterior commissure, had smaller fraction humans, suggesting disproportionally large connections accompanied reduction proportion some These findings support hypothesis an overall rearrangement during evolution. SIGNIFICANCE STATEMENT Tractography unique tool map brains different including humans. This study shows have greater monkeys, normalized volume. particular, associated language higher cognitive functions are whereas either same or smaller. supports emergence increased extended connectivity, allowing more efficient cross talk high-order associative areas temporal, parietal, occipital lobes.