Fig. 8.

Sex and hormonal status influence baseline anxiety-like behavior in the elevated zero maze, but not baseline depression-like behavior in the tail suspension test. There was a significant effect of sex, estrous cycle, and hormone supplementation on open zone entries in vehicle-treated mice. Naturally cycling female mice demonstrated increased open zone entries compared to male mice. Whereas ovariectomized female mice (supplemented or not with estrogen or progesterone) demonstrated decreased open zone entries compared to naturally cycling female mice and not significant difference compared to male mice. The open zone occupancy measure in the elevated zero maze and the immobility duration measure in the tail suspension test demonstrated no significant effect of sex, estrous cycle or hormone supplementation in vehicle-treated mice. The plots represent baseline open zone occupancy, open zone entries and immobility duration of males (♂), females (♀), females in proestrus/estrus (P/E females; ▲), females in metestrus/diestrus (M/D females; ▽), non-supplemented ovariectomized females (OVX; ○), estrogen supplemented ovariectomized females (OVX + E2; □) and progesterone supplemented ovariectomized females (OVX + P4; ◇). One-way ANOVAs were used to analyze the effect of experimental group on baseline open zone occupancy, entries, and immobility duration. The Holm’Sidak's multiple comparison test followed the significant main effect of experimental group for open zone entries. *p < 0.05, compared with males; ^☨p < 0.05, ^trp = 0.05, compared with females. See Section 3.5 (Results) for details.