The effects of a lengthy period of undernutrition from birth and subsequent nutritional rehabilitation on the granule-to-Purkinje cell ratio in the rat cerebellum.

Male rats were undernourished for various lengths of time between birth and 150 days of age, with some rats being nutritionally rehabilitated between 75 and 150 days of age. Eight control and eight experimental rats were anaesthetised and perfused with 2.5% glutaraldehyde at each of 21, 75 and 150 days of age. Stereological procedures were used to estimate granule-to-Purkinje cell ratios in lobes IV, V and VI, using 0.5 micron thick toluidine blue-stained sections. Undernourished rats had significantly lower body and cerebellar weights than controls at all ages examined. These deficits persisted even after a period of nutritional rehabilitation. The granule-to-Purkinje cells ratio did not differ between control and experimental groups at 21 or 75 days of age. However, at 150 days both undernourished and rehabilitated groups of animals had significant deficits in this ratio compared with age-matched controls. These results suggest that undernutrition can have profound effects on brain development in later life even if the effects are not apparent during the period of undernutrition.