A volumetric comparison of the insular cortex and its subregions in primates

Amy L. Bauernfeind, Alexandra A. de Sousa, Tanvi Avasthi, Seth D. Dobson, Mary Ann Raghanti, Albert H. Lewandowski, Karl Zilles, Katerina Semendeferi, John M. Allman, Arthur D.(Bud) Craig, Patrick R. Hof, Chet C. Sherwood

Research output: Contribution to journalArticlepeer-review

Abstract

The neuronal composition of the insula in primates displays a gradient, transitioning from granular neocortex in the posterior-dorsal insula to agranular neocortex in the anterior-ventral insula with an intermediate zone of dysgranularity. Additionally, apes and humans exhibit a distinctive subdomain in the agranular insula, the frontoinsular cortex (FI), defined by the presence of clusters of von Economo neurons (VENs). Studies in humans indicate that the ventral anterior insula, including agranular insular cortex and FI, is involved in social awareness, and that the posterodorsal insula, including granular and dysgranular cortices, produces an internal representation of the body's homeostatic state. We examined the volumes of these cytoarchitectural areas of insular cortex in 30 primate species, including the volume of FI in apes and humans. Results indicate that the whole insula scales hyperallometrically (exponent = 1.13) relative to total brain mass, and the agranular insula (including FI) scales against total brain mass with even greater positive allometry (exponent = 1.23), providing a potential neural basis for enhancement of social cognition in association with increased brain size. The relative volumes of the subdivisions of the insular cortex, after controlling for total brain volume, are not correlated with species typical social group size. Although its size is predicted by primate-wide allometric scaling patterns, we found that the absolute volume of the left and right agranular insula and left FI are among the most differentially expanded of the human cerebral cortex compared to our closest living relative, the chimpanzee.

Original languageEnglish (US)
Pages (from-to)263-279
Number of pages17
JournalJournal of Human Evolution
Volume64
Issue number4
DOIs
StatePublished - Apr 2013
Externally publishedYes

Keywords

  • Allometry
  • Brain
  • Evolution
  • Frontoinsular cortex
  • Hominoids

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Anthropology

Fingerprint

Dive into the research topics of 'A volumetric comparison of the insular cortex and its subregions in primates'. Together they form a unique fingerprint.

Cite this