These findings show that the reduced D1R binding and low total striatal tissue dopamine concentrations in the striatum of the THRSP-OE may be a possible result of the altered function of the SNARE complex, leading to reduced dopamine release and signaling in the brain of THRSP-OE mice, which supports the ADHD-PI-like behaviors observed in this animal model. This evidence concerns the gene DRD1 and attention deficit-hyperactivity disorder.