Young CA1 pyramidal cells of rats, but not dentate gyrus granule cells, express a delayed inward rectifying current with properties of IQ

Neurosci Lett. 1992 Feb 3;135(2):231-4. doi: 10.1016/0304-3940(92)90443-b.


In hippocampal CA1 pyramidal cells (CA1PC) and dentate gyrus granule cells (DGGC) we compared the expression of currents which could cause differences in discharge behaviour. Negative current injections cause a uniform hyperpolarization in DGGC whereas in CA1PC the initial hyperpolarization is followed by a repolarization towards resting membrane potential. The underlying inward current can be classified as IQ. It is sensitive to CsCl, activated at -80 mV, and it has a mean amplitude of -109.8 pA and a mean activation time constant of 187 ms with voltage jumps from -40 to -120 mV. We conclude that some of the differences in response properties of DGGC and CA1PC upon repetitive stimulation can be attributed to differences in the expression of IQ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cesium / pharmacology
  • Electrophysiology
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • In Vitro Techniques
  • Ion Channels / drug effects
  • Ion Channels / physiology*
  • Membrane Potentials / physiology
  • Pyramidal Tracts / cytology
  • Pyramidal Tracts / drug effects
  • Pyramidal Tracts / metabolism*
  • Rats
  • Rats, Inbred Strains


  • Ion Channels
  • Cesium