Spinal cord lipids and myelin composition in border disease (hypomyelinogenesis congenita) of lambs.

Abstract

Abstract—Spinal cords from clinically affected newborn lambs, each with muscular spasms (‘shaking’) and a ‘hairy’ birth coat, were found to be deficient in DNA and to contain less myelin and various lipid components, suggesting retarded CNS development equivalent to about 124 days conceptual age. Cerebrosides were notably deficient in whole cord and isolated myelin and contained more saturated and less unsaturated fatty acids than normal. The rate of cerebroside synthesis assayed in vitro was enhanced and taken with the very low tissue concentrations this indicated faster cerebroside turnover and a less stable myelin in the spinal cords of lambs affected with Border Disease. Marked decreases in plasmalogen concentrations, the redistribution of phospholipid fractions, the presence of about 8 per cent cholesterol in the esterified form and the characteristic fatty acid composition of these esters strongly suggest that degeneration is concomitant with myelin immaturity. Hypocupraemia, low concentrations of copper in the cerebrum and increased concentrations in spinal cord myelin are additional features of the clinical disease. The latter result may be related to myelin immaturity.