title: Variations in the structure of the prelunate gyrus in Old World monkeys.
abstract: Anatomical and electrophysiological studies have revealed a complex organization in the macaque prelunate gyrus. We investigated the morphology and architecture of the prelunate gyrus in Old World monkeys. In Macaca nemestrina, we observed a sulcus crossing the prelunate gyrus within 2 mm of the vertical meridian representation. In other macaque species and other cercopithecines, we observed substantial variations in sulcal morphology across the prelunate gyrus. We did not find a sulcus in all species, and the location and depth of that indentation on the gyrus varied among species. A deep sulcus was observed in all species that emerged earlier in evolution than macaques, such as guenons, baboons, and colobines. We analyzed the regional and parcellation features of the prelunate gyrus in three macaque species, M. maura, M. mulatta, and M. radiata, and in Erythrocebus patas, with emphasis on the relation of structure to the distribution of prelunate visual areas. Nonphosphorylated neurofilament protein immunoreactivity permitted the delineation of a novel area in the prelunate gyrus of Old World monkeys, located around the prelunate sulcus. Species-specific patterns were also observed in the prelunate gyrus of the patas monkey compared to macaques. These observations, as well as a cladistic analysis of the data, suggest an expanded and diversified organization of the prelunate gyrus in some cercopithecoids that may reflect adaptation to specific ecological environments. It was, however, progressively lost in most macaques, being retained only in species that diverged early in the evolution of the genus Macaca, such as M. nemestrina and M. maura.
authors.affiliation: Laboratory of Neuroplasticity and Neuroproteomics, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Estel
authors.initials: E
authors.lastname: Van Der Gucht
authors.forename: Michele
authors.initials: M
authors.lastname: Youakim
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Arckens
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Hof
authors.forename: Joan S
authors.initials: JS
authors.lastname: Baizer
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002520:Cercopithecidae / Q000033:anatomy & histology*; D004901:Erythrocebus patas; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008254:Macaca nemestrina; D016900:Neurofilament Proteins / Q000032:analysis; D010215:Papio; D013045:Species Specificity; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000166:cytology
chemical_list: D016900:Neurofilament Proteins