Figure 3.

Time spent in (%) and total entries into the open arms of an elevated plus maze. Data are shown as the mean ± SEM for a 5-min test. (A and D) The results from B6 mice are included as examples of the typical strong preference of wild-type mice for the closed arms. (B) BALB/c and (C) 129/Sv male mice. (E) BALB/c and (F) 129/Sv female mice. Data from a BALB/c female mouse in the nest-only group that jumped off of the maze during the test are missing. #, Value significantly (P < 0.05) different from those for both other enrichment conditions.