STXBP1 and Encephalopathy: Guided by the phenotypes of constitutive haploinsufficient mice Stxbp1tm1d/+ and Stxbp1tm1a/+ (Chen et al., 2020) and symptoms of STXBP1 encephalopathy patients, we sought to characterize the neurological functions of male and female Viaat-cHet and Vglut2-cHet mice in comparison with their sex- and age-matched control littermates to dissect the contributions of GABAergic/glycinergic and glutamatergic neurons to STXBP1 encephalopathy pathogenesis (see Extended Data Table 2-3 for the details of mouse cohorts used in the behavioral tests).