title: Co-activation of glutamate and dopamine receptors within the nucleus accumbens is required for spatial memory consolidation in mice.
abstract: BACKGROUND
  The nucleus accumbens receives glutamatergic and dopaminergic inputs converging onto common dendrites. Recent behavioral data demonstrated that intra-accumbens administrations of either glutamate or dopamine (DA) antagonist impair spatial memory consolidation. Thus, also based on the biochemical and molecular findings demonstrating interactions among the different receptors subtypes for glutamate and dopamine, it is conceivable that memory consolidation within this structure might be modulated by glutamate-dopamine receptor interactions.
  
  
  OBJECTIVE
  The purpose of this study was to examine the effects of intra-accumbens co-administrations of glutamate and DA antagonists on the consolidation of spatial information.
  
  
  METHODS
  On day 1, CD1 male mice were placed in an open field containing five different objects and immediately after three sessions of habituation the animals were injected intra-accumbens with either vehicle or low doses of the N-methyl-D: -aspartate (NMDA; AP-5 50 ng/side), the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA; DNQX 5 ng/side), the D1 (SCH23390 12.5 ng/side) and the D2 (sulpiride 25 ng/side) antagonists that were ineffective alone in disrupting object displacement. Separate groups were then focally injected with a combination of one of the glutamate antagonists with one of the dopamine antagonists. Twenty-four hours later, the ability of mice to discriminate object displacement was assessed.
  
  
  RESULTS
  Controls and mice injected with ineffective doses of the NMDA, the AMPA, the D1 or the D2 antagonists were always able to react to the object displacement. On the contrary, the groups administered with the different combinations (AP-5 and SCH23390, AP-5 and sulpiride, DNQX and SCH23390, DNQX and sulpiride) of glutamate and dopamine antagonists did not discriminate the spatial change.
  
  
  CONCLUSIONS
  These results demonstrate that glutamate-dopamine receptor interactions within the accumbens are essential for the consolidation process of spatial information.
authors.affiliation: Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, 00185 Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Ferretti
authors.forename: Cédrick
authors.initials: C
authors.lastname: Florian
authors.forename: Vivian J A
authors.initials: VJ
authors.lastname: Costantini
authors.forename: Pascal
authors.initials: P
authors.lastname: Roullet
authors.forename: Arianna
authors.initials: A
authors.lastname: Rinaldi
authors.forename: Elvira
authors.initials: E
authors.lastname: De Leonibus
authors.forename: Alberto
authors.initials: A
authors.lastname: Oliverio
authors.forename: Andrea
authors.initials: A
authors.lastname: Mele
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D009714:Nucleus Accumbens / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000502:physiology*; D017470:Receptors, Glutamate / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D011810:Quinoxalines; D011954:Receptors, Dopamine; D017470:Receptors, Glutamate; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate; D013469:Sulpiride