MYELIN-ASSOCIATED glycoprotein (MAG) inhibits neurite outgrowth of postnatal spinal cord neurons, but its effect on embryonic neurons is unknown. The effect on neurite outgrowth of another myelin protein, myelinoligodendrocyte glycoprotein (MOG) is also unknown. We determined the effect of MAG and MOG on embryonic day 17 spinal cord neurons, which were cultured on MAG, MOG or control transfected CHO cells. Neurite outgrowth was examined and both total neurite length and longest neurite length were significantly enhanced by both MAG and MOG. These findings show that, in contrast to postnatal spinal cord neurons, MAG can enhance neurite outgrowth of embryonic spinal cord neurons. In addition, another myelin protein, MOG, can also modulate neurite outgrowth.