Effects of vitamin B-6 deficiency on the developing central nervous system of the rat. Myelination.

The effects of different levels of dietary pyridoxine (1.0, 1.2, 1.4, and 20.0 mg/kg diet) fed to dams during growth, gestation and lactation on myelination in progeny were investigated. Degree of myelination at 15 days, postnatally, was determined from closely matched micrographs of the four dietary treatment groups. Electron micrographs showed markedly less myelination in the 1.0 group as compared with the 1.4 and 20.0 groups with the 1.2 group appearing intermediate in the number of myelinated axons. Some myelinated axons of the 1.0 group exhibited an "unusual" appearance of whorls of lamina separated by cytoplasmic space occupied by widely separated lamina. The results indicate that brain development, particularly myelination, was affected by a deficiency of vitamin B-6 prior to and including the period of rapid myelination.