title: Dopamine D5 receptors are localized at asymmetric synapses in the rat hippocampus.
abstract: Functional studies indicate that the dopamine D5 receptor is involved in synaptic transmission in the hippocampus. However, previous anatomical studies have detected D5 receptor labelling primarily on the soma and main dendrites of CA1 pyramidal cells and on dendritic spines in monkey but not in rats. In order to get a better understanding of putative dopamine function in the hippocampus, we quantified the D5 receptor immunoreactivity on the pyramidal cell somas and on spines and dendrites in stratum radiatum and stratum oriens in the hippocampal CA1 region of rats by quantitative immunofluorescence and immunogold electron microscopy. The quantitative immunogold results revealed a higher labelling density on dendritic spines, notably at their synaptic membranes, compared to pyramidal cell somas and dendrites. Hence, dopamine could have effects on spines as well as on somas and dendrites. The labelling density was similar on spines in stratum oriens and stratum radiatum, but the presence of labelling varied between the spines within each stratum, indicating that the effect of dopamine could be diverse between different spines.
authors.affiliation: The Brain and Muscle Energy Group, Centre for Molecular Biology and Neuroscience and Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, PB1105 Blindern, N-0317 Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Medin
authors.forename: S G
authors.initials: SG
authors.lastname: Owe
authors.forename: J E
authors.initials: JE
authors.lastname: Rinholm
authors.forename: M
authors.initials: M
authors.lastname: Larsson
authors.forename: T
authors.initials: T
authors.lastname: Sagvolden
authors.forename: J
authors.initials: J
authors.lastname: Storm-Mathisen
authors.forename: L H
authors.initials: LH
authors.lastname: Bergersen
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry; D056547:CA1 Region, Hippocampal / Q000737:chemistry* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D046529:Microscopy, Electron, Transmission; D051381:Rats; D017208:Rats, Wistar; D050641:Receptors, Dopamine D5 / Q000032:analysis* / Q000378:metabolism; D013569:Synapses / Q000737:chemistry* / Q000378:metabolism
chemical_list: D050641:Receptors, Dopamine D5