title: Optical analysis of acute spontaneous epileptiform discharges in the in vivo rat cerebral cortex.
abstract: We examined the spatiotemporal patterns of spontaneous epileptiform activity observed in the in vivo rat cerebral cortex using an optical recording technique of detecting transmembrane voltage changes. The surface of the cerebral cortex was exposed under anesthesia and stained with a fluorescent voltage-sensitive dye, RH414. Acute spontaneous epileptiform discharges were induced by application of a GABA(A) receptor antagonist, bicuculline. Changes in the intensity of fluorescence were recorded from the cerebral cortex using a 464-channel optic fiber photodiode system. We succeeded in recording spontaneous epileptiform discharges, and constructed their initiation-site maps. We found that the initiation site was neither unique nor randomly located, but exhibited a multimodal distribution pattern. The incidence of epileptiform discharges was different between the initiation sites, and some sites showed dominance in the induction of spontaneous epileptiform discharges.
authors.affiliation: Department of Physiology and Cell Biology, Tokyo Medical and Dental University Graduate School and Faculty of Medicine, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Miyakawa
authors.forename: Itaru
authors.initials: I
authors.lastname: Yazawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Yoko
authors.initials: Y
authors.lastname: Momose-Sato
authors.forename: Katsushige
authors.initials: K
authors.lastname: Sato
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D003952:Diagnostic Imaging / Q000295:instrumentation*; D004569:Electroencephalography / Q000295:instrumentation*; D004827:Epilepsy / Q000139:chemically induced / Q000503:physiopathology*; D005456:Fluorescent Dyes; D058787:GABA-A Receptor Antagonists; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D011726:Pyridinium Compounds; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005456:Fluorescent Dyes; D058787:GABA-A Receptor Antagonists; D011726:Pyridinium Compounds; C054158:RH 414; D001640:Bicuculline