Intrainsular functional connectivity in human
Article first published online: 12 SEP 2013
Copyright © 2013 Wiley Periodicals, Inc.
Human Brain Mapping
Volume 35, Issue 6, pages 2779–2788, June 2014
How to Cite
Almashaikhi, T., Rheims, S., Ostrowsky-Coste, K., Montavont, A., Jung, J., De Bellescize, J., Arzimanoglou, A., Keo Kosal, P., Guénot, M., Bertrand, O. and Ryvlin, P. (2014), Intrainsular functional connectivity in human. Hum. Brain Mapp., 35: 2779–2788. doi: 10.1002/hbm.22366
- Issue published online: 21 APR 2014
- Article first published online: 12 SEP 2013
- Manuscript Accepted: 25 JUN 2013
- Manuscript Revised: 21 JUN 2013
- Manuscript Received: 27 MAR 2013
- functional connectivity;
- intra-cranial electrical stimulation;
- evoked potential;
The anatomical organization of the insular cortex is characterized by its rich and heterogeneous cytoarchitecture and its wide network of connections. However, only limited knowledge is available regarding the intrainsular connections subserving the complex integrative role of the insular cortex. The aim of this study was to analyze the functional connectivity within- and across-insular subregions, at both gyral and functional levels.
We performed intracerebral electrical stimulation in 10 patients with refractory epilepsy investigated with depth electrodes, 38 of which were inserted in the insula. Bipolar electrical stimulation, consisting of two series of 20 pulses of 1-ms duration, 0.2-Hz frequency, and 1-mA intensity, was delivered at each insular contact. For each stimulated insular anatomical region, we calculated a rate of connectivity, reflecting the proportion of other insular contacts, showing significant evoked potentials.
Statistically significant evoked potentials were recorded in 74% of tested connections, with an average latency of 26 ± 3 ms. All insular gyri were interconnected, except the anterior and posterior short gyri. Most connections were reciprocal, showing no clear anterior to posterior directionality. No connection was observed between the right and the left insula.
These findings point to specific features of human insula connectivity as compared to non-Human primates, and remain consistent with the complex integration role devoted to the human insula in many cognitive domains. Hum Brain Mapp 35:2779–2788, 2014. © 2013 Wiley Periodicals, Inc.