Genetic Disruption of 2-Arachidonoylglycerol Synthesis Reveals a Key Role for Endocannabinoid Signaling in Anxiety Modulation

•DAGLα deletion reduces CNS, but not circulating, 2-AG levels•DAGLα knockout mice exhibit anxiety and sex-specific depressive behaviors•DAGLα deletion impairs endocannabinoid suppression of amygdala glutamate release•Normalizing 2-AG levels reverses the behavioral phenotype of DAGLα-deficient mice

SummaryEndocannabinoid (eCB) signaling has been heavily implicated in the modulation of anxiety and depressive behaviors and emotional learning. However, the role of the most-abundant endocannabinoid 2-arachidonoylglycerol (2-AG) in the physiological regulation of affective behaviors is not well understood. Here, we show that genetic deletion of the 2-AG synthetic enzyme diacylglycerol lipase α (DAGLα) in mice reduces brain, but not circulating, 2-AG levels. DAGLα deletion also results in anxiety-like and sex-specific anhedonic phenotypes associated with impaired activity-dependent eCB retrograde signaling at amygdala glutamatergic synapses. Importantly, acute pharmacological normalization of 2-AG levels reverses both phenotypes of DAGLα-deficient mice. These data suggest 2-AG deficiency could contribute to the pathogenesis of affective disorders and that pharmacological normalization of 2-AG signaling could represent an approach for the treatment of mood and anxiety disorders.

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