title: Striatal Neurons Expressing D1and D2Receptors are Morphologically Distinct and Differently Affected by Dopamine Denervation in Mice.
abstract: The loss of nigrostriatal dopamine neurons in Parkinson's disease induces a reduction in the number of dendritic spines on medium spiny neurons (MSNs) of the striatum expressing D1or D2dopamine receptor. Consequences on MSNs expressing both receptors (D1/D2MSNs) are currently unknown. We looked for changes induced by dopamine denervation in the density, regional distribution and morphological features of D1/D2MSNs, by comparing 6-OHDA-lesioned double BAC transgenic mice (Drd1a-tdTomato/Drd2-EGFP) to sham-lesioned animals. D1/D2MSNs are uniformly distributed throughout the dorsal striatum (1.9% of MSNs). In contrast, they are heterogeneously distributed and more numerous in the ventral striatum (14.6% in the shell and 7.3% in the core). Compared to D1and D2MSNs, D1/D2MSNs are endowed with a smaller cell body and a less profusely arborized dendritic tree with less dendritic spines. The dendritic spine density of D1/D2MSNs, but also of D1and D2MSNs, is significantly reduced in 6-OHDA-lesioned mice. In contrast to D1and D2MSNs, the extent of dendritic arborization of D1/D2MSNs appears unaltered in 6-OHDA-lesioned mice. Our data indicate that D1/D2MSNs in the mouse striatum form a distinct neuronal population that is affected differently by dopamine deafferentation that characterizes Parkinson's disease.
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Gagnon
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Petryszyn
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: M G
authors.initials: MG
authors.lastname: Sanchez
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Bories
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Beaulieu
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: De Koninck
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Parent
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Parent
mesh_terms: D000818:Animals; D049229:Dendritic Spines / Q000378:metabolism; D003714:Denervation; D004298:Dopamine / Q000378:metabolism*; D004399:Dynorphins / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism; D008822:Mice, Transgenic; D017072:Neostriatum / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000378:metabolism / Q000473:pathology; D016627:Oxidopamine; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism / Q000473:pathology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D017557:Ventral Tegmental Area / Q000378:metabolism / Q000473:pathology
chemical_list: D004745:Enkephalins; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D004399:Dynorphins; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine