A number of prior findings suggest a potential link between FAAH, anandamide and extinction. First, extinction increases anandamide, but not 2-arachidonoylglycerol, levels in the mouse basolateral amygdala (BLA),3 a brain region critical for extinction.13,14 Second, constitutive deletion of the mouse FAAH gene promotes extinction of a spatial reference memory.15 Third, systemic administration of the endocannabinoid reuptake blocker AM404, which nonspecifically increases both anandamide and 2-arachidonoylglycerol,16 increases fear memory and/or extinction in rats.17,18
