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

Summary 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).