Conditional knock-in mice expressing the dominant-negative GNAO1 G203R mutation in specific circuits reveal striatal and forebrain contributions to seizures and motor deficits, region-specific synaptic and proteomic alterations, and that caffeine treatment rescues motor abnormalities.

Though focused on pediatric GNAO1 encephalopathy, the study provides circuit-specific dissection of G protein signaling, molecular biomarkers, and a repurposed intervention (caffeine), offering experimental strategies and translational leads that could inform Parkinson's motor-circuit targeting and…

BACKGROUND: Neurodevelopmental disorders feature various symptoms that frequently include seizures and motor manifestations, but their attribution to disruptions of specific circuits and molecular alterations is notoriously hard to establish, which limits therapeutic interventions. Among these, is the GNAO1 disorder a severe pediatric encephalopathy associated with mutations in a gene encoding G protein subunit Gαo, a key transducer of neuromodulatory responses mediated by a vast number of G protein-coupled receptors. METHODS: In this study, we introduce a unique approach to modeling GNAO1 disorder, and neurodevelopmental disorders in general, by creating a conditional knock-in mouse model of a severe dominant negative GNAO1 variant G203R that allows circuit-specific induction of the mutation. A comprehensive battery of behavioral tests, together with electrophysiological recordings and proteomic analysis, was used to assess motor performance, seizure susceptibility, as well as molecular and functional alterations associated with the disorder. RESULTS: The model allowed parsing out circuit-specific contributions of Gαo dysfunction to motor and epileptic manifestations across neurons in striatum and forebrain. We further established molecular profiles of the disorder in a region-specific manner and documented the impact on synaptic transmission. This information guided the development of an intervention strategy using caffeine, which effectively rescued motor abnormalities. CONCLUSIONS: Our results point to the essential role of Gαo in maintaining neural circuit homeostasis. This advances our understanding of GNAO1 disorder-related disease mechanisms and lays foundation for rational, circuit-based therapeutic strategies. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.