Kv4.3-mediated A-type K+ currents underlie rhythmic activity in hippocampal interneurons

J Neurosci. 2007 Feb 21;27(8):1942-53. doi: 10.1523/JNEUROSCI.3208-06.2007.


Hippocampal-dependent learning and memory processes are associated with theta frequency rhythmic activity. Interneuron and pyramidal cell network interactions underlie this activity, but contributions of interneuron voltage-gated membrane conductances remain unclear. We show that interneurons at the CA1 lacunosum-moleculare (LM) and radiatum (RAD) junction (LM/RAD) display voltage-dependent subthreshold membrane potential oscillations (MPOs) generated by voltage-gated tetrodotoxin-sensitive Na+ and 4-aminopyridine (4-AP)-sensitive K+ currents. They also exhibit prominent 4-AP-sensitive A-type K+ currents, with gating properties showing activation at subthreshold membrane potentials. We found that LM/RAD cells are part of specific interneuron subpopulations expressing the K+ channel subunit Kv4.3 and their transfection with Kv4.3 small interfering RNA selectively impaired A-type K+ currents and MPOs. Thus, our findings reveal a novel function of Kv4.3-mediated A-type K+ currents in the generation of intrinsic MPOs in specific subpopulations of interneurons that may participate in hippocampal theta-related rhythmic activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Electric Conductivity
  • Hippocampus / cytology
  • Hippocampus / physiology*
  • Humans
  • In Vitro Techniques
  • Interneurons / physiology*
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Oscillometry
  • Periodicity*
  • Potassium Channels / physiology*
  • RNA, Small Interfering / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Shal Potassium Channels / antagonists & inhibitors
  • Shal Potassium Channels / genetics
  • Shal Potassium Channels / physiology*
  • Sodium Channels / physiology


  • Potassium Channels
  • RNA, Small Interfering
  • Shal Potassium Channels
  • Sodium Channels