title: Role of ventral pallidal D2 dopamine receptors in the consolidation of spatial memory.
abstract: The role of dopamine (DA) receptors in spatial memory consolidation has been demonstrated in numerous brain regions, among others in the nucleus accumbens which innervates the ventral pallidum (VP). The VP contains both D1 and D2 DA receptors. We have recently shown that the VP D1 DA receptor activation facilitates consolidation of spatial memory in Morris water maze test. In the present study, the role of VP D2 DA receptors was investigated in the same paradigm. In the first experiment, the D2 DA receptor agonist quinpirole was administered into the VP of male Wistar rats in three doses (0.1, 1.0 or 5.0μg, respectively in 0.4μl physiological saline). In the second experiment, the D2 DA receptor antagonist sulpiride was applied to elucidate whether it can antagonise the effects of quinpirole. The antagonist (4.0μg, dissolved in 0.4μl physiological saline) was microinjected into the VP either by itself or prior to 1.0μg agonist treatment. Control animals received saline in both experiments. The two higher doses (1.0 and 5.0μg) of the agonist accelerated memory consolidation relative to controls and increased the stability of the consolidated memory against extinction. Sulpiride pretreatment antagonised the effects of quinpirole. In addition, the antagonist microinjected into the VP immediately after the second conditioning trial impaired learning functions. The present data provide evidences for the important role of VP D2 DA receptors in the consolidation and stabilization of spatial memory.
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Péczely
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Ollmann
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Kristóf
authors.initials: K
authors.lastname: László
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Anita
authors.initials: A
authors.lastname: Kovács
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Rita
authors.initials: R
authors.lastname: Gálosi
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Erika
authors.initials: E
authors.lastname: Kertes
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Olga
authors.initials: O
authors.lastname: Zagorácz
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary.
authors.forename: Veronika
authors.initials: V
authors.lastname: Kállai
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Karádi
authors.affiliation: Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary. Electronic address: laszlo.lenard@aok.pte.hu.
authors.forename: László
authors.initials: L
authors.lastname: Lénárd
mesh_terms: D000818:Animals; D066187:Basal Forebrain / Q000502:physiology*; D065127:Dopamine D2 Receptor Antagonists / Q000008:administration & dosage; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D019257:Quinpirole / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000502:physiology*; D065852:Spatial Memory / Q000502:physiology*; D013469:Sulpiride / Q000008:administration & dosage
chemical_list: D065127:Dopamine D2 Receptor Antagonists; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D013469:Sulpiride
keywords: D2 dopamine receptors; Memory consolidation; Morris water maze test; Quinpirole; Sulpiride; Ventral pallidum