Behavioural responses to hypergravity in the CD-1 mouse

Male and female mice were subjected to rotationally-generated hypergravity of different duration (1 or 2 h) and linear acceleration (2 or 1.08 G). Pica behaviour and spontaneous activity were investigated before, during, and after rotation. Moreover, hole-board and plus-maze tests were performed 20 min and 24 h after the end of rotation. Pica behaviour arose in the post-rotation days and was more pronounced after 1 h of 2 G exposure. Spontaneous activity was almost or totally suppressed during rotation and failed to regain the pre-rotational levels in the group exposed to 2 G for 1 h. Exploratory behaviour in the hole-board was also impaired. A clear effect of hypergravity exposure emerged in the plus maze, with 2 G mice totalizing a minor number of arm entries than the other groups and also showing an altered emotional/anxiety profile. Generally, females were more susceptible than males to the changes in gravitational environment.