title: A weighted and directed interareal connectivity matrix for macaque cerebral cortex.
abstract: Retrograde tracer injections in 29 of the 91 areas of the macaque cerebral cortex revealed 1,615 interareal pathways, a third of which have not previously been reported. A weight index (extrinsic fraction of labeled neurons [FLNe]) was determined for each area-to-area pathway. Newly found projections were weaker on average compared with the known projections; nevertheless, the 2 sets of pathways had extensively overlapping weight distributions. Repeat injections across individuals revealed modest FLNe variability given the range of FLNe values (standard deviation <1 log unit, range 5 log units). The connectivity profile for each area conformed to a lognormal distribution, where a majority of projections are moderate or weak in strength. In the G29 × 29 interareal subgraph, two-thirds of the connections that can exist do exist. Analysis of the smallest set of areas that collects links from all 91 nodes of the G29 × 91 subgraph (dominating set analysis) confirms the dense (66%) structure of the cortical matrix. The G29 × 29 subgraph suggests an unexpectedly high incidence of unidirectional links. The directed and weighted G29 × 91 connectivity matrix for the macaque will be valuable for comparison with connectivity analyses in other species, including humans. It will also inform future modeling studies that explore the regularities of cortical networks.
authors.affiliation: Stem cell and Brain Research Institute, INSERM U846, 69500 Bron, France.
authors.forename: N T
authors.initials: NT
authors.lastname: Markov
authors.forename: M M
authors.initials: MM
authors.lastname: Ercsey-Ravasz
authors.forename: A R
authors.initials: AR
authors.lastname: Ribeiro Gomes
authors.forename: C
authors.initials: C
authors.lastname: Lamy
authors.forename: L
authors.initials: L
authors.lastname: Magrou
authors.forename: J
authors.initials: J
authors.lastname: Vezoli
authors.forename: P
authors.initials: P
authors.lastname: Misery
authors.forename: A
authors.initials: A
authors.lastname: Falchier
authors.forename: R
authors.initials: R
authors.lastname: Quilodran
authors.forename: M A
authors.initials: MA
authors.lastname: Gariel
authors.forename: J
authors.initials: J
authors.lastname: Sallet
authors.forename: R
authors.initials: R
authors.lastname: Gamanut
authors.forename: C
authors.initials: C
authors.lastname: Huissoud
authors.forename: S
authors.initials: S
authors.lastname: Clavagnier
authors.forename: P
authors.initials: P
authors.lastname: Giroud
authors.forename: D
authors.initials: D
authors.lastname: Sappey-Marinier
authors.forename: P
authors.initials: P
authors.lastname: Barone
authors.forename: C
authors.initials: C
authors.lastname: Dehay
authors.forename: Z
authors.initials: Z
authors.lastname: Toroczkai
authors.forename: K
authors.initials: K
authors.lastname: Knoblauch
authors.forename: D C
authors.initials: DC
authors.lastname: Van Essen
authors.forename: H
authors.initials: H
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D007091:Image Processing, Computer-Assisted; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology*; D059906:Neuroimaging / Q000379:methods*; D056325:Neuronal Tract-Tracers
chemical_list: D056325:Neuronal Tract-Tracers