title: Morphogenic potentials of D2, D3, and D4 dopamine receptors revealed in transfected neuronal cell lines.
abstract: Molecular cloning studies have defined a family of dopamine D2-like receptors (D2, D3, and D4), which are the products of separate genes. Our previous work has shown that stimulation of dopamine D2-like receptors in cultures of fetal cortical neurons increases the extension and branching of neurites. To determine which D2-like receptors possess morphogenic potentials, a clonal mesencephalic cell line (MN9D) was transfected with D2, D3, or D4 receptor subtypes and treated with quinpirole, an agonist of D2-like receptors, and changes in morphological characteristics were quantitated. Stimulation of D2 receptors increased the number and branching of neurites with little effect on neurite extension; stimulation of D3 and D4 receptors increased the branching and extension of neurites. Similar results were found for primary mesencephalic cultures stimulated with quinpirole. These results suggest that the known D2-like receptors have specific developmental roles in regulating neuronal morphogenesis of dopaminergic pathways.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110.
authors.forename: B C
authors.initials: BC
authors.lastname: Swarzenski
authors.forename: L
authors.initials: L
authors.lastname: Tang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Oh
authors.forename: K L
authors.initials: KL
authors.lastname: O'Malley
authors.forename: R D
authors.initials: RD
authors.lastname: Todd
mesh_terms: D000818:Animals; D002460:Cell Line; D015259:Dopamine Agents / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D006801:Humans; D008636:Mesencephalon / Q000166:cytology / Q000187:drug effects; D016501:Neurites / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D019257:Quinpirole; D051381:Rats; D011954:Receptors, Dopamine / Q000235:genetics / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D012457:Salicylamides / Q000494:pharmacology; D014162:Transfection
chemical_list: C493593:DRD3 protein, human; C493599:DRD4 protein, human; D015259:Dopamine Agents; C493595:Drd3 protein, rat; C493601:Drd4 protein, rat; D004873:Ergolines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D012457:Salicylamides; D050638:Receptors, Dopamine D4; D019257:Quinpirole; C045989:eticlopride