In contrast to FAAH, MGL is a serine hydrolase that degrades 2-AG into arachidonic acid and glycerol (Dinh et al., 2002a). MGL has been shown to be an important regulator of brain 2-AG signaling in vivo (Long et al., 2009). ISH studies did not reveal a prominent hybridization signal within the rat amygdala (Dinh et al., 2002a). However, immunohistochemical studies using an N-terminal antibody against rat MGL revealed punctuate staining within the BLA, but not the CeA, of the rat amygdala (Gulyas et al., 2004). This punctuate staining was observed within the neuropil and often surrounded by unstained neurons within the BLA; furthermore, no cytoplasmic staining was observed. At the EM level, MGL was localized to a subset of axon terminals that formed both symmetric and asymmetric synapses onto MGL-negative postsynaptic dendrites (Gulyas et al., 2004). MGL expression in inhibitory axon terminals is higher in the BA than LA (Yoshida et al., 2011).
