Neurochemical evidence supporting dopamine D1-D2 receptor heteromers in the striatum of the long-tailed macaque: changes following dopaminergic manipulation.
Although it has long been widely accepted that dopamine receptor types D1 and D2 form GPCR heteromers in the striatum, the presence of D1-D2 receptor heteromers has been recently challenged. In an attempt to properly characterize D1-D2 receptor heteromers, here we have used the in situ proximity ligation assay (PLA) in striatal sections comprising the caudate nucleus, the putamen and the core and shell territories of the nucleus accumbens. Experiments were carried out in control macaques as well as in MPTP-treated animals (with and without dyskinesia). Obtained data support the presence of D1-D2 receptor heteromers within all the striatal subdivisions, with the highest abundance in the accumbens shell. Dopamine depletion by MPTP resulted in an increase of D1-D2 density in caudate and putamen which was normalized by levodopa treatment. Two different sizes of heteromers were consistently found, thus suggesting that besides individual heteromers, D1-D2 receptor heteromers are sometimes organized in macromolecular complexes made of a number of D1-D2 heteromers. Furthermore, the PLA technique was combined with different neuronal markers to properly characterize the identities of striatal neurons expressing D1-D2 heteromers. We have found that striatal projection neurons giving rise to either the direct or the indirect basal ganglia pathways expressed D1-D2 heteromers. Interestingly, macromolecular complexes of D1-D2 heteromers were only found within cholinergic interneurons. In summary, here we provide overwhelming proof that D1 and D2 receptors form heteromeric complexes in the macaque striatum, thus representing a very appealing target for a number of brain diseases involving dopamine dysfunction.
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Alberto J
AJ
Rico
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Iria G
IG
Dopeso-Reyes
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Eva
E
Martínez-Pinilla
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Diego
D
Sucunza
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Diego
D
Pignataro
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
Elvira
E
Roda
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain.
David
D
Marín-Ramos
Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.|Department of Morphological Sciences, University of Santiago de Compostela, Santiago De Compostela, Spain.
José L
JL
Labandeira-García
Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Departments of Medicine and Pharmacology, University of Toronto, Toronto, ON, Canada.
Susan R
SR
George
Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.|Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain.
Rafael
R
Franco
Department of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII Avenue 55, 31008, Pamplona, Spain. jlanciego@unav.es.|Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain. jlanciego@unav.es.
José L
JL
Lanciego
D000818:Animals; D002421:Caudate Nucleus / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D008252:Macaca fascicularis; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism; D020734:Parkinsonian Disorders; D011699:Putamen / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*
D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D004298:Dopamine
Basal ganglia; Caudate nucleus; Dyskinesia; MPTP; Putamen