Topographical assessment and pharmacological characterization of orofacialmovements in mice: dopamine D-1-like vs. D-2-like receptor regulation

A novel procedure for the assessment of orofacial movement topographies in mice was used to study, for the first time, the individual and interactive involvement of dopamine D-1-like vs. D-2-like receptors in their regulation . The dopamine D-1-like receptor agonists a 68930 ([1R,3S]-1-aminomethyl-5, 6-dihydroxy-3-phenyl-isochroman) and SK&F 83959 (3-methyl-6-chloro-7,8-dihy droxy-1-[3-methylphenyl]-2,3,il,5-tetrahydro-1H-3-benzazepine) each induced vertical jaw movements with tongue protrusions and incisor chattering. The dopamine D-1-like receptor antagonists SCH 23390 ([R]-3-methyl-7-chloro-8- hydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine) and BW 737C ([S]-6-ch loro-1-[2,5-dimethoxy-4-propylbenzyl]-7-hydroxy-2-methyl-1,2,3,4-tetrahydro isoquinoline) antagonised these responses, while the dopamine D-2-like rece ptor antagonist YM 09151-2 (cis-N-[1-benzyl-2-methyl-pyrrolidin-3-yl]-5-chl oro-2-methoxy-4-methylaminobenzamide) attenuated those to SK&F 83959 and re leased horizontal jaw movements. These findings suggest some role for a dop amine D-1-like receptor that is coupled to a transduction system other than /additional to adenylyl cyclase? and for dopamine D-1-like:D-2-like recepto r interactions, in the regulation of individual orofacial movement topograp hies in the mouse. This methodology will allow the use of knockout mice to clarify the roles of individual dopamine receptor subtypes in their regulat ion. (C) 2001 Elsevier Science B.V. All rights reserved.