N-acyldopamines control striatal input terminals via novel ligand-gated cation channels

Neuropharmacology. 2009 Mar;56(3):676-83. doi: 10.1016/j.neuropharm.2008.12.001. Epub 2008 Dec 7.

Abstract

Endogenous analogues of capsaicin, N-acyldopamines, were previously identified from striatal extracts, but the putative presynaptic role of their receptor, the TRPV(1)R (formerly: vanilloid or capsaicin receptor) in the caudate-putamen is unclear. We found that the endogenous TRPV(1)R agonists, N-arachidonoyldopamine (NADA) and oleoyldopamine (OLDA) with EC(50) values in the nanomolar range, as well as the synthetic TRPV(1)R activator 2-aminoethoxydiphenylborane (2APB), and palmytoyldopamine (PALDA, another endogenous N-acyldopamine inactive at the TRPV(1)R), but not capsaicin or other endogenous and synthetic cannabinoids, triggered a rapid Ca(2+) entry with the concomitant stimulation of glutamate and dopamine release. These effects persisted in the TRPV(1)R null-mutant mice, and were insensitive to antagonists of common ionotropic receptors, to several TRPV(1)R antagonists and to the absence of K(+). Furthermore, these N-acyldopamine receptors in glutamatergic and dopaminergic terminals are different based on their different sensitivity to anandamide, capsazepine and Gd(3+) at nanomolar concentrations. Altogether, novel ion channels instead of the TRPV(1)R mediate the presynaptic action of N-acyldopamines in the striatum of adult rodents.

MeSH terms

  • Animals
  • Arachidonic Acids / pharmacology
  • Boron Compounds / pharmacology
  • Capsaicin / analogs & derivatives*
  • Capsaicin / pharmacology
  • Cations
  • Corpus Striatum / drug effects*
  • Dopamine / analogs & derivatives
  • Dopamine / metabolism
  • Dopamine / pharmacology
  • Endocannabinoids
  • Glutamic Acid / metabolism
  • Ion Channels*
  • Ligands
  • Male
  • Mice
  • Mice, Mutant Strains
  • Polyunsaturated Alkamides / pharmacology
  • Presynaptic Terminals / drug effects
  • Presynaptic Terminals / metabolism*
  • Rats
  • Rats, Wistar
  • Synaptosomes / metabolism
  • TRPV Cation Channels / agonists

Substances

  • 2-aminoethoxydiphenylborane
  • Arachidonic Acids
  • Boron Compounds
  • Cations
  • Endocannabinoids
  • Ion Channels
  • Ligands
  • Polyunsaturated Alkamides
  • TRPV Cation Channels
  • arachidonyl dopamine
  • Glutamic Acid
  • capsazepine
  • Capsaicin
  • anandamide
  • Dopamine