Outside of adipose tissue the highest concentration of lipids are in the brain [7] with phospholipids constituting 45% of total brain dry weight [8]. Docosahexaenoic acid (DHA) is the predominant PUFA in the mammalian CNS accounting for 20–50% of the fatty acid concentration in the brain while AA is also abundant in the brain and the most prevalent fatty acid in all cell types studied [9–11]. These lipids play a significant role in development and normal homeostatic functioning of the CNS [10]. Cellular membranes are possibly the largest potential substrate pools of fatty acids in biological systems. Given their ubiquitous presence in the membranes it is not surprising that the release and subsequent metabolism of fatty acids to many types of bioactive lipid metabolites are highly regulated events.
