Mice undernourished before, but not after, weaning perform better in motor coordination and spatial learning tasks than well-fed controls.

Undernutrition of rodents has been claimed to result in long-term behavioural deficits in motor coordination and spatial learning ability, although the literature on this is somewhat conflicting. We have recently been engaged in a study of the effects of either pre- or post-weaning undernutrition on longevity in mice. As part of this ageing study, we have also assessed the effects of such nutritional regimes on motor coordination and spatial learning ability of mice. Motor coordination was tested in 21-week-old control and previously undernourished mice by assessing their ability to remain on a revolving drum. We have found that mice previously undernourished either during the pre- or post-weaning period performed better than controls during some, but not all, of the test days. Spatial learning was tested in 50-58-week-old mice using the Morris water maze. In this instance we found that mice previously undernourished during the pre-weaning period performed better at this task than either controls or mice undernourished for a period after weaning. It seems that undernutrition during the pre-weaning period may, paradoxically, improve the performance of mice in these behavioural tasks compared to controls. Undernutrition after weaning had little or no effect on these behavioural measures. The exact mechanisms involved in causing the observed long-term changes in functional capacity due to a period of undernutrition from conception until weaning age of the mice in our study remain unknown.