Recent trends in marijuana legislation have been a topic of significant public attention. Legalization of the drug in many US and overseas countries will increase its daily usage, which in turn will necessitate the need to understand the fundamental mechanisms underlying marijuana’s effect in vivo, as it remains rudimentary. Δ9-tetrahydrocannabinol (THC), the main psychoactive ingredient in marijuana interferes with the endogenous cannabinoid system (eCBs), which includes cannabinoid receptors, endogenous ligands, and enzymes involved in the synthesis and metabolism of these ligands. The eCBs modulate various cognitive and physiological processes associated with addiction including reward, stress responsiveness and appetite stimulation. Limited functional studies of eCBs have been carried out in zebrafish, which have relied on the use of morpholinos and THC treatment but little is known regarding the role of eCBs on brain development. Through genomic analysis we identified components of eCBs in the zebrafish genome, which include:
• orthologous receptors (Cb1 and Cb2)
• synthesis enzymes (Abdh4, Daglα and Daglβ)
• catabolic enzymes (Faah and Mgll)
• cannabinoid receptor 1 interacting proteins (Cnrip1A and Cnrip1B)
Here we show expression analysis of eCBs genes in the zebrafish in different embryo time points and within tissue types in adults. To further characterize the molecular mechanisms by which endocannabinoid system works we targeted and disrupted eCBs associated genes using CRISPR/Cas9 technology. We successfully generated F1 hets with indels for all the eCB genes and obtained F2 for the majority of them. Here I am presenting the preliminary characterization of these mutants revealing new insights into the mechanism of action of eCBs on neurodevelopment, physiology and behaviour.