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In vivo optical mapping of epileptic foci and surround inhibition in ferret cerebral cortex

Nature Medicine volume 7, pages 1063–1067 (2001)Cite this article

Abstract

The population of neurons participating in an epileptiform event varies from moment to moment. Most techniques currently used to localize epileptiform events in vivo have spatial and/or temporal sampling limitations. Here we show in an animal model that optical imaging based on intrinsic signals is an excellent method for in vivo mapping of clinically relevant epileptiform events, such as interictal spikes, ictal onsets, ictal spread and secondary homotopic foci. In addition, a decrease in the optical signal correlates spatially with a decrease in neuronal activity recorded from cortex surrounding an epileptic focus. Optical mapping of epilepsy might be a useful adjunct in the surgical treatment of neocortical epilepsy, which critically depends on the precise localization of intrinsically epileptogenic neurons.

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Figure 1: Optical recording of intrinsic signals demonstrate the topography of an interictal focus.
Figure 2: Spike-triggered epilepsy maps can be generated from the time-course of the optical signal.
Figure 3: Spike-triggered inverted optical signal in 'surround' corresponds with neuronal inhibition.
Figure 4: Optical imaging of seizures and homotopic secondary foci.

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Acknowledgements

We thank S. Schütt for contributions to the data analysis; F. Sengpiel and M. Hübener for advice throughout the study and, along with A. Kriegstein, for comments on the manuscript; and V. Staiger, I. Kehrer and F. Brinkmann for providing outstanding technical assistance. This work was supported by the Max-Planck Gesellschaft as well as by grants to T.H.S. from the Epilepsy Foundation of America, the van Wagenen Fellowship of the American Association of Neurological Surgeons and the Alexander von Humboldt Stiftung.

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  1. Max-Planck Institut für Neurobiologie, München-Martinsried, Germany

    Theodore H. Schwartz & Tobias Bonhoeffer

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Correspondence to Theodore H. Schwartz.

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Schwartz, T., Bonhoeffer, T. In vivo optical mapping of epileptic foci and surround inhibition in ferret cerebral cortex. Nat Med 7, 1063–1067 (2001). https://doi.org/10.1038/nm0901-1063

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