title: Mapping the hierarchical layout of the structural network of the macaque prefrontal cortex.
abstract: A consensus on the prefrontal cortex (PFC) holds that it is pivotal for flexible behavior and the integration of the cognitive, affective, and motivational domains. Certain models have been put forth and a dominant model postulates a hierarchical anterior-posterior gradient. The structural connectivity principles of this model dictate that increasingly anterior PFC regions exhibit more efferent connections toward posterior ones than vice versa. Such hierarchical asymmetry principles are thought to pertain to the macaque PFC. Additionally, the laminar patterns of the connectivity of PFC regions can be used for defining hierarchies. In the current study, we formally tested the asymmetry-based hierarchical principles of the anterior-posterior model by employing an exhaustive dataset on macaque PFC connectivity and tools from network science. On the one hand, the asymmetry-based principles and predictions of the hierarchical anterior-posterior model were not confirmed. The wiring of the macaque PFC does not fully correspond to the principles of the model, and its asymmetry-based hierarchical layout does not follow a strict anterior-posterior gradient. On the other hand, our results suggest that the laminar-based hierarchy seems a more tenable working hypothesis for models advocating an anterior-posterior gradient. Our results can inform models of the human PFC.
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht 6229 ER, The Netherlands and.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Goulas
authors.forename: Harry B M
authors.initials: HB
authors.lastname: Uylings
authors.forename: Peter
authors.initials: P
authors.lastname: Stiers
mesh_terms: D000818:Animals; D001931:Brain Mapping; D066264:Datasets as Topic; D008251:Macaca; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000033:anatomy & histology*; D017397:Prefrontal Cortex / Q000033:anatomy & histology*