Correlative biochemical and morphological studies of myelination in human ontogenesis. II. Myelination of the nerve roots.

Biochemical and morphological observations of nerve roots in six fetuses from the 16th to 34th week of gestation and five infants 1 day to 3 years old are presented. In dorsal roots the process of myelination begins later than in the ventral roots and spinal cord and proceeds much slower. As in the spinal cord during nerve roots myelin maturation profound lipid changes are observed.