Quantitative histochemistry of the spinal motor neurone nucleus during human fetal development

A quantitative histochemical study of the developing anterior horn cell nucleus was undertaken. The DNA, the arginine and lysine-rich histones as well as the acidic nuclear proteins of the spinal motor neurone nucleus were estimated during normal fetal development by means of scanning microdensitometry. The arginine-rich histones and the acidic nuclear proteins were found to be increased at the 12-14 week period, a finding which suggests that this period is critical in the differentiation of the spinal motor neurone.