title: Resonance in neocortical neurons and networks.
abstract: Neocortical networks produce oscillations that often correspond to characteristic physiological or pathological patterns. However, the mechanisms underlying the generation of and the transitions between such oscillatory states remain poorly understood. In this study, we examined resonance in mouse layer V neocortical pyramidal neurons. To accomplish this, we employed standard electrophysiology to describe cellular resonance parameters. Bode plot analysis revealed a range of resonance magnitude values in layer V neurons and demonstrated that both magnitude and phase response characteristics of layer V neocortical pyramidal neurons are modulated by changes in the extracellular environment. Specifically, increased resonant frequencies and total inductive areas were observed at higher extracellular potassium concentrations and more hyperpolarised membrane potentials. Experiments using pharmacological agents suggested that current through hyperpolarization-activated cyclic nucleotide-gated channels (I(h) ) acts as the primary driver of resonance in these neurons, with other potassium currents, such as A-type potassium current and delayed-rectifier potassium current (Kv1.4 and Kv1.1, respectively), contributing auxiliary roles. The persistent sodium current was also shown to play a role in amplifying the magnitude of resonance without contributing significantly to the phase response. Although resonance effects in individual neurons are small, their properties embedded in large networks may significantly affect network behavior and may have potential implications for pathological processes.
authors.affiliation: Department of Pediatrics, Section of Neurology, The University of Chicago, 900 E. 57th Street, Room 4122, Chicago, IL 60637, USA. jdwyer1@uchicago.edu
authors.forename: Jennifer
authors.initials: J
authors.lastname: Dwyer
authors.forename: Hyong
authors.initials: H
authors.lastname: Lee
authors.forename: Amber
authors.initials: A
authors.lastname: Martell
authors.forename: Wim
authors.initials: W
authors.lastname: van Drongelen
mesh_terms: D000818:Animals; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000037:antagonists & inhibitors / Q000502:physiology; D051662:Kv1.1 Potassium Channel / Q000037:antagonists & inhibitors / Q000502:physiology; D051665:Kv1.4 Potassium Channel / Q000037:antagonists & inhibitors / Q000502:physiology; D008564:Membrane Potentials; D051379:Mice; D008815:Mice, Inbred Strains; D019579:Neocortex / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000494:pharmacology; D017966:Pyramidal Cells / Q000502:physiology*; D012964:Sodium / Q000378:metabolism
chemical_list: D054815:Cyclic Nucleotide-Gated Cation Channels; D051665:Kv1.4 Potassium Channel; D026902:Potassium Channel Blockers; D051662:Kv1.1 Potassium Channel; D012964:Sodium; D011188:Potassium