title: Transient and rapid activation of Akt/GSK-3β and mTORC1 signaling by D3 dopamine receptor stimulation in dorsal striatum and nucleus accumbens.
abstract: D2/D3 dopamine receptors (D2R/D3R) agonists regulate Akt, but their effects display a complex time-course. In addition, the respective roles of D2R and D3R are not defined and downstream targets remain poorly characterized, especially in vivo. These issues were addressed here for D3R. Systemic administration of quinelorane, a D2R/D3R agonist, transiently increased phosphorylation of Akt and GSK-3β in rat nucleus accumbens and dorsal striatum with maximal effects 10 min after injection. Akt activation was associated with phosphorylation of several effectors of the mammalian target of rapamycin complex 1 (mTORC1): p70S6 kinase, ribosomal protein-S6 (Ser240/244), and eukaryotic initiation factor-4E binding protein-1. The action of quinelorane was antagonized by a D2/D3R antagonist, raclopride, and the selective D3R antagonist S33084, inactive by themselves. Furthermore, no effect of quinerolane was seen in knock-out mice lacking D3R. In drd1a-EGFP transgenic mice, quinelorane activated Akt/GSK-3β in both neurons expressing and lacking D1 receptor. Thus, the stimulation of D3R transiently activates the Akt/GSK-3β pathway in the two populations of medium-size spiny neurons of the nucleus accumbens and dorsal striatum. This effect may contribute to the influence of D3R ligands on reward, cognition, and processes disrupted in schizophrenia, drug abuse, and Parkinson's disease.
authors: Institut National de la Santé et de la Recherche Médicale-Inserm, Paris, France.
authors: Marie-Josèphe
authors: MJ
authors: Salles
authors: Denis
authors: D
authors: Hervé
authors: Jean-Michel
authors: JM
authors: Rivet
authors: Sophie
authors: S
authors: Longueville
authors: Mark J
authors: MJ
authors: Millan
authors: Jean-Antoine
authors: JA
authors: Girault
authors: Clotilde
authors: C
authors: Mannoury la Cour
mesh_terms: D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D008297:Male; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D046912:Multiprotein Complexes; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D011506:Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D058570:TOR Serine-Threonine Kinases
chemical_list: D018491:Dopamine Agonists; D046912:Multiprotein Complexes; D011506:Proteins; D011804:Quinolines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C514862:Akt1 protein, mouse; C494920:Akt1 protein, rat; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; C000605508:Gsk3b protein, rat; D000076222:Mechanistic Target of Rapamycin Complex 1; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D038362:Glycogen Synthase Kinase 3; C047726:quinelorane