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Comparative phenotypic resolution of spontaneous, D 2 ‐like and D 1 ‐like agonist‐induced orofacial movement topographies in congenic mutants with dopamine D 2 vs. D 3 receptor “knockout”
Author(s) -
Tomiyama Katsunori,
Mcnamara Fergal N.,
Clifford Jeremiah J.,
Kinsella Anthony,
Drago John,
Fuchs Sara,
Grandy David K.,
Low Malcolm J.,
Rubinstein Marcelo,
Tighe Orna,
Croke David T.,
Koshikawa Noriaki,
Waddington John L.
Publication year - 2004
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.10284
Subject(s) - mutant , receptor , neuroscience , tongue , agonist , biology , anatomy , genetics , gene , medicine , pathology
Abstract Using a novel system, the role of D 2 ‐like dopamine receptors in distinct topographies of orofacial movement was assessed in mutant mice with congenic D 2 vs. D 3 receptor knockout, and compared with findings in D 1A mutants. Under spontaneous conditions, D 2 mutants evidenced increased vertical jaw movements and unaltered horizontal jaw movements, with reductions in tongue protrusions and incisor chattering; in D 3 mutants, only incisor chattering was reduced. Given previous evidence that D 1A mutants show reduced horizontal but not vertical jaw movements, this indicates that apparent oppositional D 1 ‐like:D 2 ‐like interactions in the regulation of composited jaw movements may in fact reflect the independent actions of D 2 receptors to inhibit vertical jaw movements and of D 1A receptors to facilitate horizontal jaw movements. Effects of the D 2 ‐like agonist RU 24213 to exert greater reduction in horizontal than in vertical jaw movements were not altered prominently in either D 2 or D 3 mutants. The D 1 ‐like agonists A 68930 and SK&F 83959 induced vertical jaw movements, tongue protrusions, and incisor chattering; induction of tongue protrusions by A 68930 was reduced in D 2 mutants. D 2 receptors exert topographically specific regulation of orofacial movements in a manner distinct from their D 1A counterparts, while D 3 receptors exert only minor regulation of such movements. Synapse 51:71–81, 2004. © 2003 Wiley‐Liss, Inc.