title: In vitro recordings of human neocortical oscillations.
abstract: Electrophysiological oscillations are thought to create temporal windows of communication between brain regions. We show here that human cortical slices maintained in vitro can generate oscillations similar to those observed in vivo. We have characterized these oscillations using local field potential and whole-cell recordings obtained from neocortical slices acquired during epilepsy surgery. We confirmed that such neocortical slices maintain the necessary cellular and circuitry components, and in particular inhibitory mechanisms, to manifest oscillatory activity when exposed to glutamatergic and cholinergic agonists. The generation of oscillations was dependent on intact synaptic activity and muscarinic receptors. Such oscillations differed in electrographic and pharmacological properties from epileptiform activity. Two types of activity, theta oscillations and high gamma activity, uniquely characterized this model-activity not typically observed in animal cortical slices. We observed theta oscillations to be synchronous across cortical laminae suggesting a novel role of theta as a substrate for interlaminar communication. As well, we observed cross-frequency coupling (CFC) between theta phase and high gamma amplitude similar to that observed in vivo. The high gamma "bursts" generated by such CFC varied in their frequency content, suggesting that this variability may underlie the broadband nature of high gamma activity.
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: C M
authors.initials: CM
authors.lastname: Florez
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: R J
authors.initials: RJ
authors.lastname: McGinn
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: V
authors.initials: V
authors.lastname: Lukankin
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: I
authors.initials: I
authors.lastname: Marwa
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: S
authors.initials: S
authors.lastname: Sugumar
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8.
authors.forename: J
authors.initials: J
authors.lastname: Dian
authors.affiliation: Department of Neuropathology, Toronto General Hospital, Toronto, ON, Canada M5G 2C4 Tanz Center for Research in Neurodegenerative Diseases, Toronto, ON, Canada M5S 3H2.
authors.forename: L N
authors.initials: LN
authors.lastname: Hazrati
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Krembil Neuroscience Center, Toronto, ON, Canada, M5T 2S8 Division of Neurology, Faculty of Medicine and.
authors.forename: P L
authors.initials: PL
authors.lastname: Carlen
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Division of Neurology, Faculty of Medicine and.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Krembil Neuroscience Center, Toronto, ON, Canada, M5T 2S8 Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada, M5T 1P5.
authors.forename: T A
authors.initials: TA
authors.lastname: Valiante
mesh_terms: D000328:Adult; D000368:Aged; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005260:Female; D065818:Gamma Rhythm / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008875:Middle Aged; D019579:Neocortex / Q000187:drug effects / Q000502:physiology*; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D011976:Receptors, Muscarinic / Q000502:physiology; D013702:Temporal Lobe / Q000187:drug effects / Q000502:physiology*; D013826:Theta Rhythm / Q000187:drug effects; D055815:Young Adult
chemical_list: D018679:Cholinergic Agonists; D018690:Excitatory Amino Acid Agonists; D011976:Receptors, Muscarinic; D002217:Carbachol; D007608:Kainic Acid
keywords: cross-frequency coupling; electrophysiology; gamma; human cortex; oscillations; theta