Dopamine-galanin receptor heteromers modulate cholinergic neurotransmission in the rat ventral hippocampus

Estefanía Moreno, Sandra H Vaz, Ning-Sheng Cai, Carla Ferrada, César Quiroz, Sandeep Kumar Barodia, Nadine Kabbani, Enric I Canela, Peter J McCormick, Carme Lluis, Rafael Franco, Joaquim A Ribeiro, Ana M Sebastião, Sergi Ferré

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)

Abstract

Previous studies have shown that dopamine and galanin modulate cholinergic transmission in the hippocampus, but little is known about the mechanisms involved and their possible interactions. By using resonance energy transfer techniques in transfected mammalian cells, we demonstrated the existence of heteromers between the dopamine D(1)-like receptors (D(1) and D(5)) and galanin Gal(1), but not Gal(2) receptors. Within the D(1)-Gal(1) and D(5)-Gal(1) receptor heteromers, dopamine receptor activation potentiated and dopamine receptor blockade counteracted MAPK activation induced by stimulation of Gal(1) receptors, whereas Gal(1) receptor activation or blockade did not modify D(1)-like receptor-mediated MAPK activation. Ability of a D(1)-like receptor antagonist to block galanin-induced MAPK activation (cross-antagonism) was used as a "biochemical fingerprint" of D(1)-like-Gal(1) receptor heteromers, allowing their identification in the rat ventral hippocampus. The functional role of D(1)-like-Gal receptor heteromers was demonstrated in synaptosomes from rat ventral hippocampus, where galanin facilitated acetylcholine release, but only with costimulation of D(1)-like receptors. Electrophysiological experiments in rat ventral hippocampal slices showed that these receptor interactions modulate hippocampal synaptic transmission. Thus, a D(1)-like receptor agonist that was ineffective when administered alone turned an inhibitory effect of galanin into an excitatory effect, an interaction that required cholinergic neurotransmission. Altogether, our results strongly suggest that D(1)-like-Gal(1) receptor heteromers act as processors that integrate signals of two different neurotransmitters, dopamine and galanin, to modulate hippocampal cholinergic neurotransmission.
Original languageEnglish
Pages (from-to)7412-23
Number of pages12
JournalThe Journal of Neuroscience
Volume31
Issue number20
DOIs
Publication statusPublished - 18 May 2011

Keywords

  • Animals
  • CHO Cells
  • Cholinergic Fibers
  • Cricetinae
  • Cricetulus
  • HEK293 Cells
  • Hippocampus
  • Humans
  • Luciferases, Renilla
  • Male
  • Rats
  • Rats, Wistar
  • Receptor, Galanin, Type 1
  • Receptors, Dopamine
  • Receptors, Dopamine D1
  • Receptors, Dopamine D5
  • Receptors, Galanin
  • Synaptic Transmission

Cite this