Meeting Abstract

P3.45  Tuesday, Jan. 6  A Map of Sensory Projections to the Insular Cerebral Cortex. JOHNSON, J. I.*; MORRIS, J. A.; FOBBS, A. J.; Mchigan State Univ.; Michigan State Univ.; National Museum of Health and Medicine, Armed Forces Institute of Pathology johnij@aol.com

To construct a map of sensory projection regions in cerebral cortex of the insula, we reviewed data from studies of human, monkey, rodent and cat brains. This map shows a distribution of sensory inputs in concordance with our hypothesis of the insula as a hub of sensory cortical areas. The antero-inferior extremity of the insula lies next to, and has multiple interconnections with, primary olfactory cortex; it is agranular cortex: a virtual absence of inner granular layer IV. Posterior to, and well connected with, this olfactory region, is the wide expanse of the Primary Taste Cortex, characterized by dysgranular cortex: an intermittent layer IV. Around the Taste Region are sensory inputs from Visceral Afferents, including those involved in cardiopulmonary, digestive, and urinary bladder regulation. In the posteriormost insula is granulous cortex: a well-developed and continuous layer IV. Most superiorly within this posterior granulous region, close to primary and secondary somatosensory cortex, are somatotopically organized Thermosensory and Mechanosensory projections. Posterior and inferior to these, at the posterior insular extremity, are mixed Vestibular and Visual projections. Auditory projections lie more inferior, close to Auditory regions in the superior temporal gyrus. There are extensive interconnections between the respective sensory regions, and between these regions and executive output regions of the superior anterior agranular insular cortex.