title: Ionic Basis for Membrane Potential Resonance in Neurons of the Inferior Olive.
abstract: Some neurons have the ability to enhance output voltage to input current with a preferred frequency, which is called resonance. Resonance is thought to be a basis for membrane potential oscillation. Although ion channels responsible for resonance have been reported, the precise mechanisms by which these channels work remain poorly understood. We have found that resonance is reduced but clearly present in the inferior olivary neurons of Cav3.1 T-type voltage-dependent Ca(2+) channel knockout (KO) mice. The activation of Cav3.1 channels is strongly membrane potential dependent, but less frequency dependent. Residual resonance in Cav3.1 KO mice is abolished by a hyper-polarization-activated cyclic nucleotide-gated (HCN) channel blocker, ZD7288, and is partially suppressed by voltage-dependent K(+) channel blockers. Resonance is inhibited by ZD7288 in wild-type mice and impaired in HCN1 KO mice, suggesting that the HCN1 channel is essential for resonance. The ZD7288-sensitive current is nearly sinusoidal and strongly frequency dependent. These results suggest that Cav3.1 and HCN1 channels act as amplifying and resonating conductances, respectively.
authors.affiliation: Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Matsumoto-Makidono
authors.affiliation: Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan.
authors.forename: Hisako
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan.
authors.forename: Miwako
authors.initials: M
authors.lastname: Yamasaki
authors.affiliation: Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kano
authors.affiliation: Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakimura
authors.affiliation: Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan. Electronic address: hashik@hiroshima-u.ac.jp.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D000818:Animals; D020747:Calcium Channels, T-Type / Q000378:metabolism; D002525:Cerebellar Cortex / Q000378:metabolism* / Q000502:physiology*; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000378:metabolism; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D015221:Potassium Channels / Q000378:metabolism
chemical_list: C498197:Cacna1g protein, mouse; D020747:Calcium Channels, T-Type; D054815:Cyclic Nucleotide-Gated Cation Channels; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015221:Potassium Channels