Daglb, or diacylglycerol lipase β, is the main synthase responsible for generating 2-arachidonoyl-glycerol (2-AG), the most abundant endocannabinoid in the brain. The endocannabinoid system, in which Daglb-mediated 2-AG biosynthesis is a key part, is involved in regulating diverse neural functions. It has implications in multiple biological processes and diseases, making it an important gene for study, especially with the help of genetic models [1,2].

Genetic knockdown of Daglb in nigral dopaminergic neurons (DANs) of mice substantially reduced substantia nigra (SN) 2-AG levels and impaired locomotor skill learning, particularly across-session learning. This indicates that DAGLB-deficiency contributes to the pathogenesis of Parkinsonism, highlighting the importance of DAGLB-mediated 2-AG biosynthesis in nigral DANs in regulating neuronal activity and dopamine release [1]. In addition, in AP-4-deficient neurons (where AP-4 is involved in anterograde axonal transport), DAGLB accumulates at the trans-Golgi network, axonal DAGLB levels are reduced, and 2-AG levels in the brains of AP-4 knockout mice are decreased. Neurite growth defects of these neurons can be rescued by inhibiting the enzyme responsible for 2-AG hydrolysis, suggesting a role for DAGLB-mediated 2-AG signaling in axon growth [2].

In conclusion, Daglb is crucial for endocannabinoid synthesis, especially in the brain. Studies using gene-knockout mouse models have revealed its significant role in Parkinsonism pathogenesis and axon growth. Understanding Daglb's functions provides insights into neural function regulation and potential therapeutic targets for related neurological disorders.