Accelerated myelinogenesis induced by dietary lipids in rats

Our previous work has shown an early development of behavioral reflexes in the offspring of rats maintained on diets containing a lipid fraction extracted from yeast (Candida lypolitica) grown on n-alkanes during pregnancy and throughout lactation. Since some of these changes could be linked to an early myelination, in this study we investigated myelin maturation in the rat brain by immunohistochemistry. At 7 days the test groups showed considerable immunopositivity to myelin basic protein and proteolipid protein at a more rostral level, such as the corpus callosum where immunopositivity is usually detected later in brain development. At 7 days in controls, staining fibers were detected only in the lower brainstem and in the cerebellum. Immunopositivity in the same regions was more intense in the test groups. Some litters were fostered at birth to produce 2 groups of animals: pups whose mothers were fed a control diet prenatally and the test diet postnatally, and vice versa. Positive fibers are already present at 7 days in the telencephalon area in both groups. These data indicate that dietary lipids can interfere with brain development by accelerating myelinogenesis.