Locomotor development in undernourished rats.

The effects of undernutrition on the development of locomotion were studied in fourteen rats. Mothers received about 40% of normal quantities of standard laboratory food from the 5th day of gestation until weaning at the 21st day after birth. Qualitative as well as quantitative aspects of locomotion were studied from the 12th to the 30th day and compared to data from ten control rats. Undernutrition leads to delayed and prolonged developmental changes in locomotion. The adult type of locomotion, which in normal rats develops from the 14th day occurs after the 15th or 16th day in undernourished rats and this development also lasts longer. Locomotion remains mildly abnormal, at least until the 30th day. Especially at lower speeds, walking is clumsy because of an unusual brisk onset, a slightly unsteady gait and non-fluent paw movements. These results are discussed in the perspective of data on brain and muscle development in rats after early undernutrition.