GRIN1 and Anxiety: In the present study, we used a comprehensive battery of behavioral tests to analyze the physical and behavioral profiles of an ENU-generated mutant mouse strain (Grin1Rgsc174/Grin1+) with a non-synonymous mutation in Grin1. Grin1Rgsc174/Grin1+ mice exhibited increased locomotor activity, abnormal anxiety-like behaviors, severe deficits in fear memory, moderately impaired spatial working memory, and decreased acoustic startle responses.