The effect of fatty acid deficient diet on the developing optic nerve of the rat

Axon-myelin interrelationship was analysed morphometrically in developing optic nerves of Wistar rats maintained during the maturation on normal, lipid deficient and lipid enriched diets. The results obtained lead to the following conclusions: Myelinogenesis in the optic nerve of Wistar rats is severely retarded in animals maintained on a fatty acid deficient diet during the last period of intrauterine life and during their whole postnatal life. The axon diameter of the optic nerves in animals fed on a fatty acid deficient diet is normal in the first weeks of postnatal development, but it does not reach the values of normal ones in the young adult animals. The dietary deficit of fatty acids caused qualitative changes in the myelin-axon interrelationship in the course of myelinogenesis as indicated by an altered distribution of the ratios in the number of myelin lamellae to the axon diameter (the regression equation has changed from a linear to a parabolic one). Comparison of the morphometric and chemical studies of the developing myelin in the fatty acid deficiency experiments testify that the numerically normal myelin in young adult animals is still deficient in basic lipid classes.