GRIN2B and Anxiety: When Grin2b+/C456Y pups (P4–12) were tested for the emission of USVs upon mother separation, a measure of anxiety in rodents responsive to anxiolytic medications [45], these pups showed strongly enhanced USVs, as determined by the total number of USV calls, duration of each USV calls, and latency to first calls (Fig 3J–3L).