Effects of acute and repeated daily exposure to hypergravity on spatial learning in mice

Studies in humans have revealed that exposure to altered gravity may lead to impairments in cognitive functions. The objective of this study was to test whether mice exposed to hypergravity using a centrifuge apparatus showed learning impairments in a spatial learning task. Mice rotating at 1G or at 2G acceleration gravity and non-rotating controls were tested for reactivity to a spatial change after either a single 1 h or five repeated 1 h daily rotations in the centrifuge. While no differences among groups were found in the performance after single exposure to altered gravity, 5 days of repeated exposures to 1 G or 2G gravity conditions significantly affected mouse ability to discriminate a new spatial arrangement. Additionally, this effect was stronger in the animals repeatedly exposed to 2G rather than to 1 G conditions. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.