Physostigmine modulation of acetylcholine currents in COS cells transfected with mouse muscle nicotinic receptor

Neurosci Lett. 2006 Jun 19;401(1-2):20-4. doi: 10.1016/j.neulet.2006.02.065. Epub 2006 Mar 13.


Physostigmine (Phy), a reversible inhibitor of acetylcholine (ACh) esterase (AChE), may also act as a low potency agonist and a modulator of the nicotinic receptor. The actions of Phy on mouse muscle nicotinic receptors in the COS-7 cell line were studied by the patch-clamp technique. Currents were recorded in the whole-cell mode 3-7 days after cell transfection by plasmids coding alphabetagammadelta combination of receptor subunits. The application of ACh to cells clamped at -10 mV produced inward currents which displayed desensitization. The application of Phy in concentrations up to 1 x 10(-3) M did not give reliable specific whole-cell membrane responses. The application of Phy in concentrations of 10(-6)-10(-4) M together with ACh modulated the amplitude; accelerated desensitization of currents induced by ACh and increased the final extent of desensitization in a concentration-dependent manner. This finding is in contrast to the suppression and slowing down of desensitization by Phy and 1-methyl-galanthamine observed in Torpedo receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism*
  • Acetylcholine / pharmacology
  • Animals
  • COS Cells
  • Cell Membrane / drug effects
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Chlorocebus aethiops
  • Cholinesterase Inhibitors / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Synergism
  • Genetic Vectors / genetics
  • Ion Channels / drug effects
  • Ion Channels / genetics
  • Ion Channels / metabolism
  • Membrane Potentials / drug effects
  • Membrane Potentials / genetics
  • Mice
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / metabolism*
  • Neuromuscular Junction / drug effects
  • Neuromuscular Junction / metabolism*
  • Patch-Clamp Techniques
  • Physostigmine / pharmacology*
  • Receptors, Nicotinic / drug effects
  • Receptors, Nicotinic / genetics
  • Receptors, Nicotinic / metabolism*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / genetics*
  • Transfection


  • Cholinesterase Inhibitors
  • Ion Channels
  • Receptors, Nicotinic
  • Physostigmine
  • Acetylcholine