Neuritic acid is an important component of brain phospholipids during normal development

The fatty acid composition of phosphatidylethanolamine (PE), ethanolamine plasmalogens (EPs), phosphatidylserine (PS), phosphatidylcholine (PC), and sphingomyelin was studied in 22 human forebrains。Docosahexaenoic acid (22:6n‐3) increased with age in PE and PC, whereas arachidonic acid (20:4n‐6) remained quite constant. In EP, 22:6n‐3 increased less markedly than 20:4n‐6, adrenic (22:4n‐6) and oleic (18:1n‐9) acids being the predominant fatty acids during postnatal age. As a characteristic myelin lipid, sphingomyelin was mainly constituted by very long chain saturated and monounsaturated fatty acids. Among them, nervonic acid (24:1n‐9) was the major very long chain fatty acid in Sp, followed by 24:0, 26:1n‐9, and 26:0, and its accretion after birth was dramatic.

Fatty acids in the developing forebrain of humans, expressed in the form of nmol/g, are mapped with age (logarithmic scale). Compared with the PuFAs long-chain unsaturated fatty acids in the previous figure, all four fatty acids showed a gradual increase from about term, consistent with the time of myelin formation. The best fitting of this curve growth is obtained by using the cubic polynomial equation. The results of the nmur9 family show the developmental changes of two oleic acid products, 24:1n‐9 (nervonic acid) and 26:ln-9, in brain Sp. For comparison, we added their saturated counterparts 24:0 (lignin acid) and 26:0 (glutamic acid), which are also typical representatives of myelin phospholipids. It can be seen that nervonic acid is by far the most important long fatty acid in Sp, and it accumulates most rapidly in the process of myelin formation.