Do astroglial cells participate in the process of human spinal cord myelination?

The material comprised spinal cord segments C8 or Th1 of 6 human fetuses aged from 16-17 up to 34 weeks and 6 infants aged from one day to 3 years. On formalin-fixed, paraffin-embedded sections, peroxidase-antiperoxidase Sternberger's et al. (1970) method for visualization of astrocytic proteins (S-100 and GFAP), myelin basic protein (MBP) and neuron specific enolase (NSE), was used. Parallelly to the increasing immunoreactivity to MBP, more S-100 and GFAP-positive cells were observed. Immunoreactivity to S-100 was more distinct in astrocytic perikarya, whereas, in GFAP reaction immunostaining of astrocytic processes was more pronounced. It is very difficult to explain why reactivity of astrocytes appears during myelination.