title: MRI-based localization of electrophysiological recording sites within the cerebral cortex at single-voxel accuracy.
abstract: The localization of microelectrode recording sites in the layers of primate cerebral cortex permits the analysis of relationships between recorded neuronal activities and underlying anatomical connections. We present a magnetic resonance imaging method for precise in vivo localization of cortical recording sites. In this method, the susceptibility-induced effect thickens the appearance of the microelectrode and enhances the detectability of the microelectrode tip, which usually occupies less than a few percent of the volume of an image voxel. In a phantom study, the optimized susceptibility-induced effect allowed tip detection with single-voxel accuracy (in-plane resolution, 50 mum). We applied this method to recording microelectrodes inserted into the brains of macaque monkeys, and localized the microelectrode tip at an in-plane resolution of 150 mum within the cortex of 2-3 mm in thickness. Subsequent histological analyses validated the single-voxel accuracy of the in vivo tip localization. This method opens up a way to investigate information flow during cognitive processes in the brain.
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Matsui
authors.forename: Kenji W
authors.initials: KW
authors.lastname: Koyano
authors.forename: Minoru
authors.initials: M
authors.lastname: Koyama
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nakahara
authors.forename: Masaki
authors.initials: M
authors.lastname: Takeda
authors.forename: Yohei
authors.initials: Y
authors.lastname: Ohashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Naya
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyashita
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004594:Electrophysiology / Q000379:methods*; D008251:Macaca; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008839:Microelectrodes; D019047:Phantoms, Imaging