In vitro recordings of human neocortical oscillations

Cereb Cortex. 2015 Mar;25(3):578-97. doi: 10.1093/cercor/bht235. Epub 2013 Sep 17.


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.

Keywords: cross-frequency coupling; electrophysiology; gamma; human cortex; oscillations; theta.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Carbachol / pharmacology
  • Cholinergic Agonists / pharmacology
  • Excitatory Amino Acid Agonists / pharmacology
  • Female
  • Gamma Rhythm* / drug effects
  • Humans
  • In Vitro Techniques
  • Interneurons / drug effects
  • Interneurons / physiology*
  • Kainic Acid / pharmacology
  • Male
  • Membrane Potentials / drug effects
  • Middle Aged
  • Neocortex / drug effects
  • Neocortex / physiology*
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology*
  • Receptors, Muscarinic / physiology
  • Temporal Lobe / drug effects
  • Temporal Lobe / physiology*
  • Theta Rhythm* / drug effects
  • Young Adult


  • Cholinergic Agonists
  • Excitatory Amino Acid Agonists
  • Receptors, Muscarinic
  • Carbachol
  • Kainic Acid