Orofacial movements in phospholipase C‐related catalytically inactive protein‐1/2 double knockout mice: Effect of the GABAergic agent diazepam and the D₁ dopamine receptor agonist SKF 83959

Abstract

Orofacial movements are regulated by D(1)-like dopamine receptors interacting with additional mechanisms. Phospholipase C-related catalytically inactive protein (PRIP) regulates cell surface expression of GABA(A) receptors containing a gamma2 subunit. Mutant mice with double knockout of PRIP-1 and PRIP-2 were used to investigate aspects of GABAergic regulation of orofacial movements and interactions with D(1) mechanisms. Vertical jaw movements, tongue protrusions and movements of the head and vibrissae were reduced in PRIP-1/2 double knockouts. The GABA(A)ergic agent diazepam reduced movements of the head and vibrissae; these effects were unaltered in PRIP-1/2 double knockouts. The D(1)-like agonist SKF 83959 induced vertical jaw movements, incisor chattering, and movements of the head and vibrissae that were unaltered in PRIP-1/2 double knockouts. However, SKF 83959-induced tongue protrusions were reduced in PRIP-1/2 double knockouts. PRIP-mediated regulation of GABA(A)ergic receptor mechanisms influences topographically distinct aspects of orofacial movement and interacts with D(1) receptor systems.

Modelling the neuromotor abnormalities of psychotic illness: Putative mechanisms and systems dysfunction

“…Mutant mice with constitutive co-deletion of the proteins PRIP-1 and PRIP2, which regulate the assembly and trafficking of GABAA receptors, show a decrease in tongue protrusions, with disrupted habituation of vertical jaw, head and vibrissae movements (Tomiyama et al, 2010). In mice with constitutive deletion of the GABA synthesising enzyme GAD65, vertical jaw movements are reduced (Tomiyama et al, 2013).…”