The effect of pre- and postnatal undernutrition on the calibre growth of central motor fibres

Abstract
The effect of early in life instituted undernutrition on the calibre growth of cortico-spinal motor fibres was studied electron microscopically at three different developmental stages in the rat. The total diameters of these motor fibres were measured from a defined level of the medulla oblongata and plotted in histograms. In undernourished rats the calibre growth was retarded as compared to agematched control rats. Early initiated nutritional rehabilitation through controlled cross-fostering revealed that the impaired calibre growth was reversible, and thus completely restituted at the age of 180 days. It is concluded that early initiated protein-calorie undernutrition affects this central motor pathway in a similar way, as it affects a peripheral motor nerve (cf. Sima, 1974).