TIP39-KO spent less time in the open arms (a) and made fewer open arm entries (b), but did not differ in closed arm entries (c) when compared with WT in the elevated plus-maze following restraint stress (no restraint; WT, n = 10, KO, n = 8; restraint; WT, n = 8, KO, n = 14). TIP39-KO spent less time in the open arms (d) and made fewer open arm entries (e), while closed arm entries were not significantly changed (f) when compared with WT controls under high, but not low, illumination levels in the elevated plus-maze (low illumination; WT, n = 8/genotype; high illumination; WT, n = 9, KO, n = 8). WT, open bars; KO, solid bars. Data are mean ± SEM. **P < 0.01.