eCBs comprise a family of arachidonic acid-derived lipid molecules synthesized by vertebrate and invertebrate animals (Piomelli, 2003; Di Marzo et al., 2005). eCBs include 2-arachidonoylglycerol (2-AG), anandamide (AEA), noladin ether, and several other candidate molecules. 2-AG is synthesized by conversion of sn-2 arachidonic acid containing diacylglycerols to the monoacylglycerol 2-AG, via an sn-1-specific diacylglycerol lipase (DAGL) (Bisogno et al., 2003) and is degraded primarily by monoacylglycerol lipase (MGL)(Dinh et al., 2002b; Blankman et al., 2007). On the other hand, synthesis of AEA has been demonstrated to occur via multiple pathways but is degraded primarily by fatty acid amide hydrolase (FAAH) (Cravatt and Lichtman, 2002; Ahn et al., 2008; Ueda et al., 2010).
