title: Dopamine D1 receptor-induced signaling through TrkB receptors in striatal neurons.
abstract: In addition to its role as a neurotransmitter, dopamine can stimulate neurite outgrowth and morphological effects upon primary neurons. To investigate the signal transduction mechanisms used by dopamine in developing striatal neurons, we focused upon the effects of activating the dopamine D1 receptor. Using the D1 receptor agonist SKF38393, we found that Trk neurotrophin receptors were activated in embryonic day 18 striatal neurons. K-252a, a Trk tyrosine kinase inhibitor, and a dopamine D1 receptor antagonist could block the effects of SKF38393. The increase in TrkB phosphorylation was not the result of increased neurotrophin production. Induction of TrkB activity by SKF38393 was accompanied by the phosphorylation of several Trk signaling proteins, including phospholipase Cgamma, Akt, and MAPK. Biotinylation experiments followed by immunostaining by phospho-TrkB-specific antibodies indicated that the mechanism involved increased TrkB surface expression by dopamine D1 receptor activation. This increase in cell surface TrkB expression was dependent upon an increase in intracellular Ca(2+). These results indicate that stimulation of dopamine D1 receptors can be coupled to the neurotrophin receptor signaling to mediate the effects of dopamine upon striatal neurons.
authors.affiliation: Molecular Neurobiology Program, Kimmel Center at Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Iwakura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sora
authors.forename: Moses V
authors.initials: MV
authors.lastname: Chao
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D026121:Indole Alkaloids / Q000494:pharmacology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D016501:Neurites / Q000378:metabolism*; D051966:Phospholipase C gamma / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011134:Polysaccharides / Q000096:biosynthesis; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
chemical_list: D002227:Carbazoles; D018491:Dopamine Agonists; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D011134:Polysaccharides; D017447:Receptors, Dopamine D1; C010491:neurotropin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; C049985:staurosporine aglycone; D020813:Receptor, trkB; D051057:Proto-Oncogene Proteins c-akt; D020929:Mitogen-Activated Protein Kinase Kinases; D051966:Phospholipase C gamma; D002118:Calcium