ACCELERATED MYELINOGENESIS INDUCED BY DIETARY LIPIDS IN RATS

Our previous work has shown an early development of behavioral reflexe s in the offspring of rats maintained on diets containing a lipid frac tion extracted from yeast (Candida lypolitica) grown on n-alkanes duri ng pregnancy and throughout lactation. Since some of these changes cou ld be linked to an early myelination, in this study we investigated my elin maturation in the rat brain by immunohistochemistry. At 7 days th e test groups showed considerable immunopositivity to myelin basic pro tein and proteolipid protein at a more rostral level, such as the corp us 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 f ostered at birth to produce 2 groups of animals: pups whose mothers we re fed a control diet prenatally and the test diet postnatally, and vi ce versa. Positive fibers are already present at 7 days in the telence phalon area in both groups. These data indicate that dietary lipids ca n interfere with brain development by accelerating myelinogenesis.