Rat OPCs were incubated in the presence of LPC 18:1 or LPC 18:0 and C13-His. Cultures controls included no treatment and a positive control for the differentiation of OPCs. LPC 18:1 was administered at 10 uM while C13-His was administered at 10 uM. Samples were process for mass spectrometry to identify the incorporation of C13-His in newly synthesized proteins.