Fig. 1.

Anxiety-related parameters were evaluated in the elevated plus maze (a), the light–dark choice test (b) and the open field test (c) in intact female C57Bl/6 N mice at different stages of the oestrous cycle. In the forced swim test, significant differences in immobility were only observed during the initial phase of the test (second to sixth minute; d), but not in the late phase (11th to 15th minute; e). No differences were observed in the tail suspension test (f). Numbers in the columns indicate the number of animals in the respective groups. *P < 0.05, **P < 0.01 vs. di-group. di met-oestrus + early dioestrus, pro late di- + early pro-oestrus, oest oestrus, as assessed by vaginal smear analyses