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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2010-9-16
pubmed:abstractText
Associative learning depends on multiple cortical and subcortical structures, including striatum, hippocampus, and amygdala. Both glutamatergic and dopaminergic neurotransmitter systems have been implicated in learning and memory consolidation. While the role of glutamate is well established, the role of dopamine and its receptors in these processes is less clear. In this study, we used two models of dopamine D(1) receptor (D(1)R, Drd1a) loss, D(1)R knock-out mice (Drd1a(-/-)) and mice with intrahippocampal injections of Drd1a-siRNA (small interfering RNA), to study the role of D(1)R in different models of learning, hippocampal long-term potentiation (LTP) and associated gene expression. D(1)R loss markedly reduced spatial learning, fear learning, and classical conditioning of the eyelid response, as well as the associated activity-dependent synaptic plasticity in the hippocampal CA1-CA3 synapse. These results provide the first experimental demonstration that D(1)R is required for trace eyeblink conditioning and associated changes in synaptic strength in hippocampus of behaving mice. Drd1a-siRNA mice were indistinguishable from Drd1a(-/-) mice in all experiments, indicating that hippocampal knockdown was as effective as global inactivation and that the observed effects are caused by loss of D(1)R and not by indirect developmental effects of Drd1a(-/-). Finally, in vivo LTP and LTP-induced expression of Egr1 in the hippocampus were significantly reduced in Drd1a(-/-) and Drd1a-siRNA, indicating an important role for D(1)R in these processes. Our data reveal a functional relationship between acquisition of associative learning, increase in synaptic strength at the CA3-CA1 synapse, and Egr1 induction in the hippocampus by demonstrating that all three are dramatically impaired when D(1)R is eliminated or reduced.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12288-300
pubmed:meshHeading
pubmed-meshheading:20844125-Animals, pubmed-meshheading:20844125-Association Learning, pubmed-meshheading:20844125-CA1 Region, Hippocampal, pubmed-meshheading:20844125-CA3 Region, Hippocampal, pubmed-meshheading:20844125-Early Growth Response Protein 1, pubmed-meshheading:20844125-Gene Expression Regulation, pubmed-meshheading:20844125-Hippocampus, pubmed-meshheading:20844125-Long-Term Potentiation, pubmed-meshheading:20844125-Male, pubmed-meshheading:20844125-Mice, pubmed-meshheading:20844125-Mice, Inbred C57BL, pubmed-meshheading:20844125-Mice, Knockout, pubmed-meshheading:20844125-Neural Inhibition, pubmed-meshheading:20844125-Neuronal Plasticity, pubmed-meshheading:20844125-RNA, Small Interfering, pubmed-meshheading:20844125-RNA Interference, pubmed-meshheading:20844125-Receptors, Dopamine D1, pubmed-meshheading:20844125-Synaptic Transmission
pubmed:year
2010
pubmed:articleTitle
Associative learning and CA3-CA1 synaptic plasticity are impaired in D1R null, Drd1a-/- mice and in hippocampal siRNA silenced Drd1a mice.
pubmed:affiliation
Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28002, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't