Nicotinic receptors that bind alpha-bungarotoxin on neurons raise intracellular free Ca2+

Neuron. 1992 Feb;8(2):353-62. doi: 10.1016/0896-6273(92)90301-s.


Many populations of vertebrate neurons have a membrane component that binds alpha-bungarotoxin and cholinergic ligands. Despite the abundance of this component and its similarities to nicotinic receptors, its function has remained controversial. Using a fluorescence assay, we show here that activation of the component elevates the intracellular concentration of free Ca2+, demonstrating a receptor function for the toxin-binding component. Whole-cell voltage-clamp and intracellular recordings did not detect a significant current resulting from receptor activation, possibly because the currents were small or the receptors rapidly desensitized. The rise in intracellular free Ca2+ caused by the receptor was prevented by Ca2+ channel blockers. This suggests a signaling cascade likely to have important regulatory consequences for the neuron.

Publication types

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

MeSH terms

  • Animals
  • Bungarotoxins / metabolism*
  • Bungarotoxins / pharmacology
  • Cadmium / pharmacology
  • Calcium / analysis
  • Calcium / metabolism*
  • Calcium Channels / drug effects
  • Calcium Channels / physiology
  • Cells, Cultured
  • Chick Embryo
  • Dose-Response Relationship, Drug
  • Fluorescence
  • Neurons / chemistry
  • Neurons / metabolism*
  • Neurons / ultrastructure
  • Nickel / pharmacology
  • Nicotine / metabolism
  • Nicotine / pharmacology
  • Nifedipine / pharmacology
  • Receptors, Nicotinic / metabolism*
  • Receptors, Nicotinic / physiology*
  • Tubocurarine / pharmacology


  • Bungarotoxins
  • Calcium Channels
  • Receptors, Nicotinic
  • Cadmium
  • Nicotine
  • Nickel
  • Nifedipine
  • Calcium
  • Tubocurarine