Dopamine modulates the afterhyperpolarization in neostriatal neurones

Neuroreport. 1996 Jan 31;7(2):454-6. doi: 10.1097/00001756-199601310-00019.

Abstract

Intracellular techniques were used to study the actions of dopaminergic D1 agonists on the afterhyperpolarization (AHP) that follows action potentials in rat neostriatal neurones. Dopamine or Cl-APB (10 microM), or 1-10 microM 6-Cl-PB all increased AHP amplitude. This effect was blocked by 1 microM SCH-23390, a D1 antagonist, but not by 1 microM sulpiride, a D2 antagonist. Both 500 microM dibutyryl cAMP and 5 microM BayK 8644 induced a similar AHP increase. BayK 8644 occluded the effect of agonists. The results suggest that the action of dopamine is mediated via the recently described protein kinase A enhancement of L-type Ca2+ channels. The results partially explain the decrease in firing frequency induced by dopamine and a possible site of antagonism with cholinergic modulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / pharmacology
  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Bucladesine / pharmacology
  • Calcium Channel Agonists / pharmacology
  • Dopamine / pharmacology
  • Dopamine / physiology*
  • Dopamine D2 Receptor Antagonists
  • In Vitro Techniques
  • Neostriatum / cytology
  • Neostriatum / drug effects
  • Neostriatum / physiology*
  • Neurons / drug effects
  • Neurons / physiology*
  • Rats
  • Receptors, Dopamine D1 / agonists
  • Receptors, Dopamine D1 / antagonists & inhibitors
  • Receptors, Dopamine D2 / agonists

Substances

  • Calcium Channel Agonists
  • Dopamine D2 Receptor Antagonists
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Bucladesine
  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
  • Dopamine