P-type calcium channels in rat central and peripheral neurons

Neuron. 1992 Jul;9(1):85-95. doi: 10.1016/0896-6273(92)90223-z.


The peptide toxin omega-Aga-IVA blocked P-type Ca2+ channel current in rat Purkinje neurons (KD approximately 2 nM) but had no effect on identified T-type, L-type, or N-type currents in a variety of central and peripheral neurons. omega-Aga-IVA blocked a substantial fraction of high threshold Ca2+ channel current in neurons from the hippocampal CA1 region (mean 26%), visual cortex (32%), spinal cord (45%), and dorsal root ganglia (23%), but less in hippocampal CA3 neurons (14%) and none in sympathetic neurons. In all cases, omega-Aga-IVA block could be reversed by a brief train of strong depolarizations. There was no overlap between current blocked by omega-Aga-IVA and the fractions blocked by dihydropyridines and omega-conotoxin GVIA, but not all current resistant to dihydropyridines and omega-conotoxin was blocked by omega-Aga-IVA. The results suggest that omega-Aga-IVA is highly selective for P-type channels and that many central neurons and some peripheral neurons possess substantial P-type current.

Publication types

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

MeSH terms

  • Animals
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / physiology
  • Calcium Channels / ultrastructure*
  • Cells, Cultured
  • Central Nervous System / cytology
  • Central Nervous System / physiology*
  • Central Nervous System / ultrastructure
  • Dihydropyridines / pharmacology
  • Electric Stimulation
  • Ganglia, Spinal / cytology
  • Hippocampus / cytology
  • Neurons / cytology
  • Neurons / physiology
  • Neurons / ultrastructure*
  • Peptides, Cyclic / pharmacology
  • Peripheral Nerves / cytology
  • Peripheral Nerves / physiology*
  • Peripheral Nerves / ultrastructure
  • Purkinje Fibers / drug effects
  • Purkinje Fibers / physiology
  • Rats
  • Spider Venoms / pharmacology
  • Spinal Cord / cytology
  • Synaptic Transmission / physiology
  • omega-Agatoxin IVA
  • omega-Conotoxin GVIA


  • Calcium Channel Blockers
  • Calcium Channels
  • Dihydropyridines
  • Peptides, Cyclic
  • Spider Venoms
  • omega-Agatoxin IVA
  • omega-Conotoxin GVIA