Seven new areas identified in the insular cortex
The insular crust has attracted researchers for many years, dating back to the early 19th century. Many studies using neuroimaging and electrocortical stimulation have provided evidence that the insula is a highly multifunctional and integrative brain region. Functions include interoception, socio-emotional processing, salience network control, prediction, and other cognitive and sensorimotor functions. The insula is involved in processing most sensory modalities, such as auditory, vestibular, gustatory, olfactory, nociceptive, thermosensory, and visual.
The HBP team from the University of Düsseldorf and the Forschungszentrum Jülich analyzed images of the dorsal anterior and posterior median insula from ten human brains. It used statistical mapping to calculate 3D probability maps of seven new areas. The maps reflect the interindividual variability and the location of the areas in a three-dimensional space.
It is likely that brain areas with differences in their cytoarchitecture – or the organization of their cellular composition – also differ in their function. Building on this hypothesis, the researchers set out to better understand the differences in the insula’s microstructure and identify areas that might correlate with its diverse and complex multifunctionality.
They found that the microstructure of the insula exhibits remarkable diversity and a wide range of cytoarchitectural features, which could underlie the complex functional organization of this brain region.
Cluster analysis resulted in the identification of three superordinate microstructural clusters in the insular cortex. These revealed significant differences in the microstructure of the anterior and posterior insula, reflecting systematic functional differences between both entities.
The maps are now available in the Human Brain Project (HBP) Multilevel Atlas of the Human Brain on BRAINS to support future studies addressing relationships between structure and function in the human insula.