Developmental profiling by mass spectrometry of phosphocholine containing phospholipids in the rat nervous system reveals temporo-spatial gradients.

Phospholipids are important components of the nervous system, in particular of neuronal and glial membranes. Ontogenesis of the nervous system is associated with fundamental alterations in lipid patterns. Here, matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry and electro-spray-ionization mass spectrometry were combined to analyze phosphatidylcholines and sphingomyelins, allowing an assessment of individual molecular species. Analysis in eight different regions of the nervous system during development of the Wistar rat, from embryonic day 14 to adulthood, produced informative patterns of developmental and regional changes in lipid contents. Phospholipids containing long chain fatty acyl residues exhibited a characteristic patterning, with dramatic increases in the caudal parts of the nervous system 2 weeks after birth. In contrast, relative contents of short chain phosphatidylcholines were low in the perinatal CNS, decreasing even further during development. The relative amounts of sphingomyelins carrying the fatty acid residues 18:0, 22:0, 24:0, and 24:1 increased developmentally in the caudal nervous system. The rostro-caudal gradient of long chain lipid accumulation is matched by expression gradients of myelin structural and regulatory genes, as evident from bioinformatic analysis. These observations characterize the accumulation of individual lipid classes in the nervous system as a highly regulated process, with structurally related lipids showing a similar temporo-spatial distribution and developmental patterning.