Inhibiting the endocannabinoid degrading enzymes FAAH and MAGL during zebrafish embryogenesis alters sensorimotor...

The endocannabinoid system (eCS) plays a critical role in a variety of homeostatic and developmental processes. Although the eCS is known to be involved in motor and sensory function, the role of endocannabinoid (eCB) signaling in sensorimotor development remains to be fully understood. In this study, the catabolic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) were inhibited either simultaneously or individually during the first ∼24 h of zebrafish embryogenesis, and the properties of contractile events and escape responses were studied in animals ranging in age from 1 day post-fertilization (dpf) to 10 weeks. This perturbation of the eCS resulted in alterations to contractile activity at 1 dpf. Inhibition of MAGL using JZL 184 and dual inhibition of FAAH/MAGL using JZL 195 decreased escape swimming activity at 2 dpf. Treatment with JZL 195 also produced alterations in the properties of the 2 dpf short latency C-start escape response. Animals treated with JZL 195 exhibited deficits in escape responses elicited by auditory/vibrational stimuli at 5 and 6 dpf. These deficits were also present during the juvenile developmental stage (8- to 10-week-old fish), demonstrating a prolonged impact to sensory systems. These findings demonstrate that eCS perturbation affects sensorimotor function, and underscores the importance of eCB signaling in the development of motor and sensory processes.