Elementary properties and pharmacological sensitivities of calcium channels in mammalian peripheral neurons

Neuron. 1989 May;2(5):1453-63. doi: 10.1016/0896-6273(89)90191-8.


The major component of whole-cell Ca2+ current in differentiated, neuron-like rat pheochromocytoma (PC12) cells and sympathetic neurons is carried by dihydropyridine-insensitive, high-threshold-activated N-type Ca2+ channels. We show that these channels have unitary properties distinct from those of previously described Ca2+ channels and contribute both slowly inactivating and large sustained components of whole-cell current. The N-type Ca2+ currents are modulated by GTP binding proteins. The snail toxin omega-conotoxin reveals two pharmacological components of N-type currents, one blocked irreversibly and one inhibited reversibly. Contrary to previous reports, neuronal L-type channels are insensitive to omega-conotoxin. N-type Ca2+ channels appear to be specific for neuronal cells, since their functional expression is greatly enhanced by nerve growth factor.

Publication types

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

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Calcium / metabolism*
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Dihydropyridines / pharmacology
  • GTP-Binding Proteins / metabolism
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Guanosine Triphosphate / analogs & derivatives
  • Guanosine Triphosphate / pharmacology
  • Ion Channel Gating / drug effects*
  • Mollusk Venoms / pharmacology
  • Neurons / metabolism
  • Pheochromocytoma / pathology
  • Rats
  • Thionucleotides / pharmacology
  • Tumor Cells, Cultured / metabolism
  • omega-Conotoxins*


  • Calcium Channels
  • Dihydropyridines
  • Mollusk Venoms
  • Thionucleotides
  • omega-Conotoxins
  • Conus magus toxin
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • 1,4-dihydropyridine
  • Guanosine Triphosphate
  • GTP-Binding Proteins
  • Acetylcholine
  • Calcium