Insula of the old world monkey. III: Efferent cortical output and comments on function

Document Type

Article

Abstract

The insula sends neural efferents to cortical areas from which it receives reciprocal afferent projections. A collective consideration of afferents and efferents indicates that the insula has connections with principal sensory areas in the olfactory, gustatory, somesthetic (SI and SII), and auditory AI and AII) modalities. There are additional connections with association areas for the visual (TEm), auditory (supratemporal plane), and somesthetic (posterior parietal cortex) modalities; with parameter cortex (area 6 and perhaps MII); with polymodal association cortex; and with a wide range of paralimbic areas in the orbital, temporopolar, and cingulate areas. The topographic distribution of these connections suggests that the posterodorsal insula is specialized for auditory‐somesthetic‐skeletomotor function whereas the anteroventral insula is related to olfactory‐gustatory‐autonomic function. Most of the insula, especially its anteroventral portions, have extensive interconnections with limbic structures. Through its connections with the amygdala, the insula provides a pathway for somatosen‐sory, auditory, gustatory, olfactory, and visceral sensations to reach the limbic system. The cortical areas connected with the granular sector of the insula are also granular in architecture whereas virtually all the connections of the agranular insula arise from allocortical, agranular, or dysgranular areas. Thus, there is a correspondence between the architecture of insular sectors and the areas with which they have connections. The insula is heavily interconnected with temporopolar and lateral orbital areas. Furthermore, many cortical connections of the lateral orbital cortex are quite similar to those of the insula. These common connectivity patterns support the conclusion, based on architectonic observations, that the insulo‐orbito‐tempo‐ropolar component of the paralimbic brain should be considered as an integrated unit of cerebral organization. Copyright © 1982 Alan R. Liss, Inc.

Publication Date

1-1-1982

Publication Title

Journal of Comparative Neurology

ISSN

00219967

E-ISSN

10969861

Volume

212

Issue

1

First Page

38

Last Page

52

PubMed ID

7174907

Digital Object Identifier (DOI)

10.1002/cne.902120104

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