P-type calcium channels in the somata and dendrites of adult cerebellar Purkinje cells

Neuron. 1992 Dec;9(6):1185-99. doi: 10.1016/0896-6273(92)90076-p.

Abstract

The pharmacological and single-channel properties of Ca2+ channels were studied in the somata and dendrites of adult cerebellar Purkinje cells. The Ca2+ channels were exclusively of the high threshold type: low threshold Ca2+ channels were not found. These high threshold channels were not blocked by omega-conotoxin GVIA and were inhibited rather than activated by BAY K 8644. They were therefore pharmacologically distinct from high threshold N- and L-type channels. Funnel web spider toxin was an effective blocker. The channels opened to conductance levels of 9, 14, and 19 pS (in 110 mM Ba2+). These slope conductances were in the range of those reported for N- and L-type channels. Our results are in agreement with previous reports suggesting that Ca2+ channels in Purkinje cells can be classified as P-type channels according to their pharmacology. The results also suggest that distinctions among Ca2+ channel types based on the single-channel conductance are not definitive.

Publication types

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

MeSH terms

  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / pharmacology
  • Animals
  • Calcium Channels / physiology*
  • Dendrites / physiology*
  • Dihydropyridines / pharmacology
  • Electric Stimulation
  • Electrophysiology / methods
  • Evoked Potentials / drug effects
  • Female
  • Guinea Pigs
  • In Vitro Techniques
  • Membrane Potentials
  • Purkinje Cells / drug effects
  • Purkinje Cells / physiology*

Substances

  • Calcium Channels
  • Dihydropyridines
  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
  • 1,4-dihydropyridine