Brief-lifetime, fast-inactivating ion channels account for the alpha-bungarotoxin-sensitive nicotinic response in hippocampal neurons

Neurosci Lett. 1993 Dec 24;164(1-2):137-40. doi: 10.1016/0304-3940(93)90876-m.


Single-channel currents underlying the various types of nicotinic receptor-gated whole-cell currents (previously termed IA, IB, II and III) were identified in rat hippocampal neurons. In response to applied acetylcholine (ACh), most of the neurons showed a fast-decaying whole-cell current (type IA) that can be blocked by alpha-bungarotoxin (alpha-BGT). In these neurons, a novel nicotinic receptor channel was found, having a conductance of 73 pS and an open time of 0.12 ms at -80 mV. This channel showed a fast concentration-dependent inactivation that had a time constant of 0.5 ms at 1 mM ACh. A high Ca2+ permeability and the involvement of alpha 7 receptor subunits in the channel structure were suggested.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Bungarotoxins / pharmacology*
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Ion Channel Gating / drug effects
  • Ion Channels / metabolism*
  • Kinetics
  • Membrane Potentials / drug effects
  • Neurons / drug effects
  • Neurons / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Nicotinic / drug effects*


  • Bungarotoxins
  • Ion Channels
  • Receptors, Nicotinic
  • Acetylcholine