Development of Anxious-Depression-Related Behavior Figure 4. Behavioral consequences of diazepam treatment during one- or two-week postnatal developmental temporal windows. a) Schematic showing the schedule of DZP treatment and behavioral testing of the five cohorts of mice analyzed. DZP was administered during P10- 16, P14-28, P22-28, P29-35 or P50-56, followed by behavioral testing between 8 and 11 weeks of age or, in the case of P29-35 and P50-56, between 4 and 9 weeks after the end of DZP treatment. b–f) In the EPMT, the percentage of open arm entries of P10-16 DZP- vs. vehicle-treated mice was reduced (b). Similarly, the percentage of open arm entries trended lower in P14-28 DZP-treated vs. vehicle treated mice (c). However, the number of closed arm entries was unaffected for both treatment periods, consistent with unaltered locomotion. By contrast, DZP treatment during P22-28, P29- 35 and P50-56 was without long-term behavioral consequences in this test (d-f). g–k) When tested in the FST, the mice treated with DZP during P10- 16, P14-28, P22-28 and P50-56 showed normal behavior compared to vehicle treated controls (g-i, k). By contrast, mice treated with DZP during P29- 35 showed a reduced latency to immobility and increased immobility duration (j). l) Increased immobility of P29-35 DZP-treated mice observed in the FST was confirmed by increased immobility duration in the TST, although the latency to assume an immobile position was unchanged. m–o) The PLOS ONE | www.plosone.org 8 October 2012 | Volume 7 | Issue 10 | e47441