title: D1 and D5 dopamine receptors participate on the consolidation of two different memories.
abstract: Memory consolidation is the process by which recently acquired information becomes stable and is modulated by different neurotransmitters depending on the structure involved and the nature of the memory. Here we evaluate the participation of both D1 and D5 dopamine receptors in the CA1 region of the hippocampus in the consolidation of the memory of two different tasks, object recognition (OR) and inhibitory avoidance (IA). For this, male rats with infusion cannulae stereotaxically implanted in the CA1 region of the dorsal hippocampus were trained in an OR task involving exposure to two different objects, or in a one-trial step-down IA task. At different times after the training, some of the animals received intrahippocampal infusions of the D1-family receptor antagonist SCH-23390. In a test session carried out 24h later, the animals that received infusions immediately or 60 min but not 180 min after the training showed impaired long-term memory. Since D1- and D5-subtypes engage different signaling pathways involving cAMP-dependent protein kinase (PKA) and protein kinase C (PKC), respectively, we assessed whether they participate distinctively in consolidation. The animals that received intra-CA1 infusions of the PKA inhibitor, Rp-cAMP, or the PKC inhibitor, Gö6976, immediately after OR or IA training had a long-term memory impairment and the amnesic effect caused by SCH-23390 was reversed when co-infused with activators of PKA (8Br-cAMP) or PKC (PMA). These results indicate that both D1 and D5 dopamine receptors are required in the CA1 region of the hippocampus for consolidation of the two tasks. This supports the notion of a commonality of consolidation mechanisms across tasks.
authors: Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor, 90610-000 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Brazil. Electronic address: cristianefurini@hotmail.com.
authors: C R G
authors: CR
authors: Furini
authors: Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor, 90610-000 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Brazil.
authors: J C
authors: JC
authors: Myskiw
authors: Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor, 90610-000 Porto Alegre, RS, Brazil.
authors: B E
authors: BE
authors: Schmidt
authors: Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor, 90610-000 Porto Alegre, RS, Brazil.
authors: L A
authors: LA
authors: Marcondes
authors: Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor, 90610-000 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Brazil.
authors: I
authors: I
authors: Izquierdo
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D001552:Benzazepines / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology; D002227:Carbazoles / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D050641:Receptors, Dopamine D5 / Q000502:physiology*; D021641:Recognition, Psychology / Q000187:drug effects
chemical_list: D001552:Benzazepines; D002227:Carbazoles; D004791:Enzyme Inhibitors; D017447:Receptors, Dopamine D1; C534628:SCH 23390; C081021:Go 6976; D050641:Receptors, Dopamine D5; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C
keywords: Consolidation; Dopamine receptors; Hippocampus; Inhibitory avoidance; Object recognition memory