Figure 1.

Social isolation of male Long-Evans rats increases expression of anxiety-like behavior in the plus maze. Following six weeks in each housing condition, group-housed (“Group”, □) and socially-isolated (“Isolated”, ■) were examined in the plus maze. (A) Social isolation significantly decreased time spent in the open arms. Numbers in parentheses indicate the number of individual animals in each group. Isolation also increased the time spent in the closed arms (B) and decreased the number of open-arm entries (C). Note the measures of locomotor activity, like the number of closed-arm entries (D), were not significantly affected by the housing experience. * – P<0.05, t-test