Laure Mazzola1,2,3, Jean-Pierre Royet4,5, Hélène Catenoix6, Alexandra Montavont6, Jean Isnard2,6, François Mauguière2,5,6. 1. Neurology Department, University Hospital, Saint-Étienne. 2. Central Integration of Pain Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028, National Center for Scientific Research Mixed Unit of Research 5292, Lyon. 3. Jean Monnet University, Saint-Étienne. 4. Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028, National Center for Scientific Research Mixed Unit of Research 5292, University of Lyon, Lyon. 5. Claude Bernard University Lyon 1, University of Lyon, Lyon. 6. Functional Neurology and Epilepsy Department, Neurological Hospital, Civil Hospices of Lyon, Lyon, France.
Abstract
OBJECTIVE: Despite numerous studies suggesting the role of insular cortex in the processing of gustatory and olfactory inputs, the exact location of olfactogustatory representation in the insula remains controversial. Here we provide a functional mapping of olfactory-gustatory responses to stimulation of the human insular cortex. METHODS: We reviewed 651 electrical stimulations of the insula that were performed in 221 patients, using stereotactically implanted depth electrodes, during the presurgical evaluation of drug-refractory epilepsy. RESULTS: Gustatory sensations were evoked in 15 (2.7%) of the 550 stimulations that elicited a clinical response. They were exclusively obtained after stimulation of a relatively delimited zone of insula, located in its mid-dorsal part (posterior short gyrus). Six olfactory sensations (1.1%) could be obtained during stimulations of an insular region that partially overlapped with the gustatory representation. INTERPRETATION: Our study provides a functional mapping of gustatory representation in the insular posterior short gyrus and the first detailed description of olfactory sensations obtained by direct stimulation of mid-dorsal insula. Our data also show a spatial overlap between gustatory, olfactory, and oral somatosensory representation in the mid-dorsal insula, and suggest that this part of the insula may be an integrated oral sensory region that plays a key role in flavor perception. It also indicates that dysfunction in this region should be considered during the evaluation of gustatory and olfactory epileptic seizures. Ann Neurol 2017;82:360-370.
OBJECTIVE: Despite numerous studies suggesting the role of insular cortex in the processing of gustatory and olfactory inputs, the exact location of olfactogustatory representation in the insula remains controversial. Here we provide a functional mapping of olfactory-gustatory responses to stimulation of the human insular cortex. METHODS: We reviewed 651 electrical stimulations of the insula that were performed in 221 patients, using stereotactically implanted depth electrodes, during the presurgical evaluation of drug-refractory epilepsy. RESULTS: Gustatory sensations were evoked in 15 (2.7%) of the 550 stimulations that elicited a clinical response. They were exclusively obtained after stimulation of a relatively delimited zone of insula, located in its mid-dorsal part (posterior short gyrus). Six olfactory sensations (1.1%) could be obtained during stimulations of an insular region that partially overlapped with the gustatory representation. INTERPRETATION: Our study provides a functional mapping of gustatory representation in the insular posterior short gyrus and the first detailed description of olfactory sensations obtained by direct stimulation of mid-dorsal insula. Our data also show a spatial overlap between gustatory, olfactory, and oral somatosensory representation in the mid-dorsal insula, and suggest that this part of the insula may be an integrated oral sensory region that plays a key role in flavor perception. It also indicates that dysfunction in this region should be considered during the evaluation of gustatory and olfactory epileptic seizures. Ann Neurol 2017;82:360-370.
Authors: Kathrin Ohla; Ryusuke Yoshida; Stephen D Roper; Patricia M Di Lorenzo; Jonathan D Victor; John D Boughter; Max Fletcher; Donald B Katz; Nirupa Chaudhari Journal: Chem Senses Date: 2019-04-15 Impact factor: 3.160